# 14-3 Home Runs From Panel



## HackWork (Oct 2, 2009)

Your profile says "06 Limited Energy" which is low voltage.

Is that a mistake? Do you have an electrical license and a legitimate and insured contracting company?


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## PlugsAndLights (Jan 19, 2016)

These are known as MWBC's and were my favourite way to wire. Now that 
(nearly) everything has to be on AFCI's, that's changed. 
P&L


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## HitDaLights (Mar 7, 2017)

Good to know, and yes, by trade I am a licensed 06, but I work for a company that also does 01/02 and 06A so I am trying to move into those fields to become more versatile. A little extracurricular study, if you will. Thanks for the confirmation, P&L what do you recommend for making sure circuits are done properly?


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## telsa (May 22, 2015)

HitDaLights said:


> Helping some friends with some interesting wiring on a 1970's house with recent renovation by non-contractors including some iffy electrical work; breaker box doesn't have a ton of cables in it for the size of the house, *but the original install they used 14-3 instead of the traditional 14-2 romex*, it appears that they did this for the home runs and used Red for one phase, black for the other as you would with double-pole breakers but they are doing this for the entire panel including separate single pole circuits over the same home run that it looks like, later, they split off for different runs on different phases over the same cable.
> 
> Is this acceptable? Is it safe? Electrical inspector passed it so I'm assuming the alternating phase makes it okay, it just presents a problem when trying to do work later and determine what phase your run is on unless you find the original drop since they don't continue to use the Red Wire on a phase through the rest of the drops, but switch back to 14-2.
> 
> They originally had me come out to switch out a GFI that had gone bad, it didn't seem that old but then I noticed it ties to a light in an adjacent room that had the two phases tied to the switch and when the switch is flipped the gfi trips. Any who, would love thoughts on this as I don't see old wiring like this and have been working it out in my head how to solve a few different issues they have.


I hope you're kidding me.


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## Southeast Power (Jan 18, 2009)

HitDaLights said:


> Helping some friends with some interesting wiring on a 1970's house with recent renovation by non-contractors including some iffy electrical work; breaker box doesn't have a ton of cables in it for the size of the house, but the original install they used 14-3 instead of the traditional 14-2 romex, it appears that they did this for the home runs and used Red for one phase, black for the other as you would with double-pole breakers but they are doing this for the entire panel including separate single pole circuits over the same home run that it looks like, later, they split off for different runs on different phases over the same cable.
> 
> Is this acceptable? Is it safe? Electrical inspector passed it so I'm assuming the alternating phase makes it okay, it just presents a problem when trying to do work later and determine what phase your run is on unless you find the original drop since they don't continue to use the Red Wire on a phase through the rest of the drops, but switch back to 14-2.
> 
> They originally had me come out to switch out a GFI that had gone bad, it didn't seem that old but then I noticed it ties to a light in an adjacent room that had the two phases tied to the switch and when the switch is flipped the gfi trips. Any who, would love thoughts on this as I don't see old wiring like this and have been working it out in my head how to solve a few different issues they have.


Nothing wrong with that except that when electricians were replaced with laborers on tract housing, that somehow became a hazard.
I remember wiring a habitat house decades ago. They said no common neutrals and I swear I thought it was such a stupid wast of money I almost walked out.


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## HackWork (Oct 2, 2009)

And to add to what Suncoast said, they made the change in 2008 prohibiting single pole breakers feeding MWBC because of laborers and unqualified people working on the circuit, just like the OP.


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## Southeast Power (Jan 18, 2009)

HackWork said:


> And to add to what Suncoast said, they made the change in 2008 prohibiting single pole breakers feeding MWBC because of laborers and unqualified people working on the circuit, just like the OP.


Coming in hard.


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## sbrn33 (Mar 15, 2007)

You should not be doing this electrical without someone who knows what they are doing supervising you.


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## HitDaLights (Mar 7, 2017)

*We all Start somewhere*

I got into the trades 3 years ago partially out of necessity for a new career but also because I wanted to learn how to work on my house, I entered in the 06 LV sector and completed my Journeyman focusing on datacomm/nursecall and DAS. I was quite green to the trades, aside from minor painting and driving nails as a kid, as I'm sure we all were at one point. And I understand the Low Voltage turds mean nothing but a pain in the ass to Sparkies in the commercial and residential spaces. Seeing as how there is an insane amount of need for Electricians especially but really all tradesmen I think everyone would benefit from inclusiveness and freedom of information. I hope one day when I'm finishing my 01 that I will be helpful to people coming into the trades so that I have more informed colleagues doing good work around me.


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## HackWork (Oct 2, 2009)

HitDaLights said:


> And I understand the Low Voltage turds mean nothing but a pain in the ass to Sparkies in the commercial and residential spaces.


 Not at all. There are many long time members here who do low voltage and are respected the same as any other electrician. I have never seen a bias here at all.



> Seeing as how there is an insane amount of need for Electricians especially but really all tradesmen I think everyone would benefit from inclusiveness and freedom of information. I hope one day when I'm finishing my 01 that I will be helpful to people coming into the trades so that I have more informed colleagues doing good work around me.


There is nothing wrong with "information". The problem is with unqualified people doing electrical work.

Your opening post to this thread is the exact reason why the code changed in 2008, because unqualified people who don't understand MWBC's were working on them.

Instead of dumbing down the code, we should be enforcing the licensing laws better. Which means you shouldn't be going out to people's houses to do electrical work.

Now if it doesn't involve you doing electrical work, and you are just interested in how MWBC's work, this is the time to ask any questions you may have.


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## HitDaLights (Mar 7, 2017)

I understand the frustration with random laborers and untrained electricians doing work and forcing the change to the NEC, I am trying to move into this field from Low Voltage, I'd like to parlay what I know about it into doing good work on electrical for my house and eventually move to either Residential or Commercial High Voltage License so I am grateful for the knowledge of the forum, I won't be doing any work that I don't know for sure I can do and haven't done anything yet that I didn't figure out first either by consulting a high-voltage colleague or my contractor friends.


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## telsa (May 22, 2015)

HitDaLights said:


> I understand the frustration with random laborers and untrained electricians doing work and forcing the change to the NEC, I am trying to move into this field from Low Voltage, I'd like to parlay what I know about it into doing good work on electrical for my house and eventually move to either Residential or Commercial High Voltage License so I am grateful for the knowledge of the forum, I won't be doing any work that I don't know for sure I can do and haven't done anything yet that I didn't figure out first either by consulting a high-voltage colleague or my contractor friends.


Apprenticeship is really the only way.

I.e. your instructor has to be side by side with you.

The actual complexity of our craft is WAY beyond perceiving by the hoi polloi.

To be a j-man is to have a graduate degree in our real world craft.

To be a master is to have a post graduate degree in our craft.

BTW, _new_ residential construction = baby steps.

Complexity explodes with _old_ work and commercial + industrial.

{ You'll be running around with your hair on fire dealing with K&T circuits. }


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## PlugsAndLights (Jan 19, 2016)

HitDaLights said:


> Good to know, and yes, by trade I am a licensed 06, but I work for a company that also does 01/02 and 06A so I am trying to move into those fields to become more versatile. A little extracurricular study, if you will. Thanks for the confirmation, P&L what do you recommend for making sure circuits are done properly?


Have a look at the attached diagram. It's pretty simple. Only common
mistake is putting both branches on the same leg at the panel. Gather 
the NEC requires they be on DP breakers and that would prevent that 
error. Have a look at other MWBC thrreads here and do a search on the 
web for same. If you still have questions. Feel free to ask me.
P&L


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## varmit (Apr 19, 2009)

At one time, this was the way home runs were installed. As others have posted, this changed to simplify things for the less skilled. This change was similar to Romex jacket being color coded - white = 14, yellow =12, orange =10.

Repair work is an entire different skill set than installation. Being good at both will make a craft person a lot more valuable.


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## LGLS (Nov 10, 2007)

Wired many homes where every HR was a multi wire branch circuit. The smoke detectors were the preferred location to split out the 14/3 to 14/2's. The fridge outlet for the 2 kitchen MWBCs. Thinking back, I can't imagine a 200a 40 cct residential panel with nothing but 2-wire HRs.


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## BlueOval5272 (Jul 25, 2015)

I do primarily residential service work and have never seen this before. Seems like the changes made making this illegal installation are for the better. Unless you calculate the load as one circuit you're running the risk of overloading your neutral. I understand that the way this is displayed in the diagram most likely takes this into account, but I guess like has been said, an uninformed electrician could easily overload the circuit when tying in new stuff. 


Sent from my iPhone using Tapatalk


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## MechanicalDVR (Dec 29, 2007)

BlueOval5272 said:


> I do primarily residential service work and have never seen this before. Seems like the changes made making this illegal installation are for the better. *Unless you calculate the load as one circuit you're running the risk of overloading your neutral*. I understand that the way this is displayed in the diagram most likely takes this into account, but I guess like has been said, an uninformed electrician could easily overload the circuit when tying in new stuff.
> 
> 
> Sent from my iPhone using Tapatalk


You do realize that when a MWBC is installed correctly there is no chance of overloading the neutral and in fact the current on the neutral is actually reduced?

MWBCs are common place in commercial work.


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## HackWork (Oct 2, 2009)

BlueOval5272 said:


> I do primarily residential service work and have never seen this before. Seems like the changes made making this illegal installation are for the better. Unless you calculate the load as one circuit you're running the risk of overloading your neutral. I understand that the way this is displayed in the diagram most likely takes this into account, but I guess like has been said, an uninformed electrician could easily overload the circuit when tying in new stuff.
> 
> 
> Sent from my iPhone using Tapatalk


This isn't true at all. 

The neutral on a MWBC only carries the imbalance of the two hots. So if both hots had 20 amps on them, the neutral would carry 0 amps. If one hot had 20 amps on it and the other hot had 0 amps on it, the neutral would carry 20 amps.

There is no way to overload a MWBC. 

Also, your idea of an electrician tying in new stuff is meaningless because it all depends on what the homeowner plugs into the outlets.


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## telsa (May 22, 2015)

BlueOval5272 said:


> I do primarily residential service work and have never seen this before. Seems like the changes made making this illegal installation are for the better.* Unless you calculate the load as one circuit you're running the risk of overloading your neutral*. I understand that the way this is displayed in the diagram most likely takes this into account, but I guess like has been said, an uninformed electrician could easily overload the circuit when tying in new stuff.
> 
> 
> Sent from my iPhone using Tapatalk


You're entirely mistaken.

Hit the books.


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## Signal1 (Feb 10, 2016)

BlueOval5272 said:


> I do primarily residential service work and have never seen this before. Seems like the changes made making this illegal installation are for the better. Unless you calculate the load as one circuit you're running the risk of overloading your neutral. I understand that the way this is displayed in the diagram most likely takes this into account, but I guess like has been said, an uninformed electrician could easily overload the circuit when tying in new stuff.
> 
> 
> Sent from my iPhone using Tapatalk


This is incorrect. MWBC's were used for decades and are very common in older homes, dominant in commercial work and are very safe when wired correctly.

The main reasons they are not common in resi anymore are
A. Dumb people
B. GFCI breakers
C. AFCI Breakers 
D. 210.4(B) which as Hax said didn't appear until 2008.


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## PlugsAndLights (Jan 19, 2016)

I'm sure I'm not the only guy here who still uses MWBC's for panel 
changes. Bring all the cct's into a few JB's. Combine as many ccts's 
as possible and bring them into the panel in MWBC's. Panel has 
fewer neutrals, fewer bonds, less clutter. Helps that we can still put
them on single poles up here. Sometimes run EMT from JB's to 
panel just cuz I like the look.....and miss bending pipe....
P&L


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## HackWork (Oct 2, 2009)

PlugsAndLights said:


> I'm sure I'm not the only guy here who still uses MWBC's for panel
> changes. Bring all the cct's into a few JB's. Combine as many ccts's
> as possible and bring them into the panel in MWBC's. Panel has
> fewer neutrals, fewer bonds, less clutter. Helps that we can still put
> ...


Nope, I can't see any reason to do all that extra work. 

I charge a lot extra when I have to move a panel and extend the circuits by adding J-boxes. I wouldn't do it for free just to have a few less neutral and grounds in the panel.


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## emtnut (Mar 1, 2015)

BlueOval5272 said:


> I do primarily residential service work and have never seen this before. Seems like the changes made making this illegal installation are for the better. Unless you calculate the load as one circuit you're running the risk of overloading your neutral. I understand that the way this is displayed in the diagram most likely takes this into account, but I guess like has been said, an uninformed electrician could easily overload the circuit when tying in new stuff.
> 
> 
> Sent from my iPhone using Tapatalk


I'd be surprised if you didn't see it !

They didn't make the install illegal, just made a tie bar required (Not up here thou ).

An uniformed electrician or DIYer, if tying into the same phase for the MWBC, is lookin to blow stuff up !


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## splatz (May 23, 2015)

PlugsAndLights said:


> I'm sure I'm not the only guy here who still uses MWBC's for panel
> changes. Bring all the cct's into a few JB's. Combine as many ccts's
> as possible and bring them into the panel in MWBC's. Panel has
> fewer neutrals, fewer bonds, less clutter. Helps that we can still put
> ...


I like the idea of having junction boxes next to the panel. I think there would be some benefits for maintenance but it could be hard to sell a customer. 

One thing would offset the work and trouble of installing the j-boxes though, you can take your time doing all the cable prep and OCD work a circuit at a time in advance of the actual panel change, then the panel change itself would go quite a bit faster / smoother.


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## Roger (Jul 7, 2007)

BlueOval5272 said:


> I do primarily residential service work and have never seen this before. Seems like the changes made making this illegal installation are for the better.


What would you cite as being illegal about a MWBC?

Here are a couple of illustrations showing how a single phase MWBC neutral works



















Roger


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## HackWork (Oct 2, 2009)

splatz said:


> I like the idea of having junction boxes next to the panel. I think there would be some benefits for maintenance but it could be hard to sell a customer.
> 
> One thing would offset the work and trouble of installing the j-boxes though, you can take your time doing all the cable prep and OCD work a circuit at a time in advance of the actual panel change, then the panel change itself would go quite a bit faster / smoother.


I am completely flabbergasted, amazed, astonished, astounded, bowled over, dumbfounded, surprised, floored, rocked, shocked, stunned, stupefied, thunderstruck. What "benefits for maintenance"? All you are doing is complicating things by adding MWBC's to junction boxes right next to the panel. How would it make maintenance any easier by not only adding another point of failure, but by adding MWBC's?

As for the panel change itself being "faster and smoother", how so? You are going to add an hour or two to the job installing the junction boxes and wiring up MWBC's. How would that help with the panel change? You should be pulling the old panel out and installing the new one. There is nothing hard or complicated about that. Spending extra hours installing and wiring up junction boxes next to the panel with MWBC's is just wasting time. It's making it harder, not easier.

This is one of the craziest things I have ever heard.


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## splatz (May 23, 2015)

HackWork said:


> I am completely flabbergasted, amazed, astonished, astounded, bowled over, dumbfounded, surprised, floored, rocked, shocked, stunned, stupefied, thunderstruck. What "benefits for maintenance"? All you are doing is complicating things by adding MWBC's to junction boxes right next to the panel. How would it make maintenance any easier by not only adding another point of failure, but by adding MWBC's?
> 
> As for the panel change itself being "faster and smoother", how so? You are going to add an hour or two to the job installing the junction boxes and wiring up MWBC's. How would that help with the panel change? You should be pulling the old panel out and installing the new one. There is nothing hard or complicated about that. Spending extra hours installing and wiring up junction boxes next to the panel with MWBC's is just wasting time. It's making it harder, not easier.
> 
> This is one of the craziest things I have ever heard.


Calm down.


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## HackWork (Oct 2, 2009)

splatz said:


> Calm down.


No, this is insanity


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## Bird dog (Oct 27, 2015)

emtnut said:


> "An uniformed electrician "QUOTE]
> 
> That's an understatement. How about unqualified?


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## telsa (May 22, 2015)

He said he was _uniformed_... not uninformed.


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## Bird dog (Oct 27, 2015)

telsa said:


> He said he was _uniformed_... not uninformed.


 Thought it was a typo.


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## eddy current (Feb 28, 2009)

MWBC are still legal in Canada. 

I used to install more of them but now with the AFCI code, you can't use them everywhere.
Did a kitchen for my cousin a few months ago and installed two of them on the counter. Split plugs have way more power available then a single pole 20 anyway.


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## emtnut (Mar 1, 2015)

Bird dog said:


> emtnut said:
> 
> 
> > "An uniformed electrician "QUOTE]
> ...


I was trying to be nice 

... maybe he wears a uniform, but yes... a typo.


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## MechanicalDVR (Dec 29, 2007)

emtnut said:


> I was trying to be nice
> 
> ... maybe he wears a uniform, but yes... a typo.


It's good to be nice to our brethren. Especially the ones that post in electrical threads. :thumbsup:


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## Southeast Power (Jan 18, 2009)

HackWork said:


> This isn't true at all.
> 
> The neutral on a MWBC only carries the imbalance of the two hots. So if both hots had 20 amps on them, the neutral would carry 0 amps. If one hot had 20 amps on it and the other hot had 0 amps on it, the neutral would carry 20 amps.
> 
> ...


WYE?:whistling2:


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## wendon (Sep 27, 2010)

I seldomly use MWBC's. Don't care for them myself. Everything is fine until the neutral connection (wire nut etc.) becomes compromised. Then watch the magic smoke disappear.

Sent from my SAMSUNG-SM-G870A using Tapatalk


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## PlugsAndLights (Jan 19, 2016)

eddy current said:


> MWBC are still legal in Canada.
> 
> I used to install more of them but now with the AFCI code, you can't use them everywhere.
> Did a kitchen for my cousin a few months ago and installed two of them on the counter. Split plugs have way more power available then a single pole 20 anyway.


Right: 3600w vs 2400w.
Good option for outlets more than 1.5m from sink (in Canada). 
P&L


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## matt1124 (Aug 23, 2011)

I did a changeout one time where the panel moved far enough nothing reached the breakers by the time I got the meter and panel where the city would allow it. I had to put junction boxes for each circuit, it was a nice clean entry into the panel but it sure was a pain!


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## eddy current (Feb 28, 2009)

wendon said:


> I seldomly use MWBC's. Don't care for them myself. Everything is fine until the neutral connection (wire nut etc.) becomes compromised. Then watch the magic smoke disappear.
> 
> Sent from my SAMSUNG-SM-G870A using Tapatalk


The service to a house is a MWBC. 3 phase services are also MWBC's. Why is it ok for a service but not anywhere else?


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## wendon (Sep 27, 2010)

eddy current said:


> The service to a house is a MWBC. 3 phase services are also MWBC's. Why is it ok for a service but not anywhere else?


You wire nut your service conductors? Does the HO climb a ladder and mess with the service drop splices? Not likely. I'm not saying they're not code compliant. I'm just saying that I don't like them. The cost of not using them on a resi job is minimal and you don't have to use DP breakers. You also don't have to shut off the lights in the room to work on the receptacle circuit......

Sent from my SAMSUNG-SM-G870A using Tapatalk


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## MechanicalDVR (Dec 29, 2007)

wendon said:


> I seldomly use MWBC's. Don't care for them myself. Everything is fine until the neutral connection (wire nut etc.) becomes compromised. Then watch the magic smoke disappear.
> 
> Sent from my SAMSUNG-SM-G870A using Tapatalk


I've used them every chance I had but now with AFCIs I guess they are pretty much a thing of the past in resi work.


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## macmikeman (Jan 23, 2007)

Backstay already posted how using double pole afci breakers is cheaper than using two single pole afci breakers. In both wire and breaker costs. I just don't care for that brand, but I recognize genius when I see it.


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## HackWork (Oct 2, 2009)

eddy current said:


> The service to a house is a MWBC. 3 phase services are also MWBC's. Why is it ok for a service but not anywhere else?


I have found that people who didn't do lots of commercial work when coming up in the trade seem to not like MWBC's.


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## RePhase277 (Feb 5, 2008)

Suncoast Power said:


> WYE?:whistling2:


Wye not?


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## Mr.Awesome (Nov 27, 2015)

HackWork said:


> I have found that people who didn't do lots of commercial work when coming up in the trade seem to not like MWBC's.


Less wires in your panel, less wires in your pipe which means less money spent on wire and likely a reduction in the size of your pipe which leads to less money spent on pipe, possibly less money spent on labour doing joints on branch circuits. Good old R Bk Bl W with colored tape and a legend on the j box is awesome.
I did learn about MWBC in a residential setting though. Early into the job I was changing out receptacles in an apartment living room. Breaker off but I still made efforts not to touch the hot but thought "the neutral is safe". Jman is hammer drilling in the kitchen when I went to grab the disconnected neutral and suddenly my arm hurt for the rest of the day. Hard education.


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