Please look at the problem statement! I (and some other people at the webboard) think that in description of walls the words "...the pair of numbers M and N define..." should be changed to "...the pair of numbers N and M define..." - M and N should be swapped both in description of horisontal and vertical walls.
I also got WA at test 2 first. But when I swapped N and M - I got AC!

It's XY order EVERYWHERE. X defines column, Y defines row.

Edited by author 03.08.2008 16:49