In this problem, all the operations should be done on the SAME computer, but I could NOT understand this from the statement, until I read the forum.
This problem is quite easy: simple bruteforce could AC in short time, but I think this bug in statement have made this problem SEEMS hard (only 100+ ACed now).

Please, fix it.

I think you can do on every computers.But doing on the same computer is the best solution.
Maybe.

Sorry my bad English.:)