dear sir,
I surely confident about my true solving about this problem.
I wanna check it again, if it's possible , also another
thing ! in the main of your problem you say find the
minimum number of citizens, but in format of output , you
ask for minimum number of conductors to be write !
what does it mean ?
 thanks, horizon team

> dear sir,
> I surely confident about my true solving about this
problem.
> I wanna check it again, if it's possible , also another
> thing ! in the main of your problem you say find the
> minimum number of citizens, but in format of output , you
> ask for minimum number of conductors to be write !
> what does it mean ?
>  thanks, horizon team

So sorry, it was a misprint. Now it's fixed. Thank you for
your notice!