I don't understand why answer for
5 5
0 0 2 0 2
0 0 0 0 0
0 0 0 0 0
0 0 0 5 0
1 0 0 4 0

must be
2 2 -1 2 -1
3 2 2 7 2
1 7 7 5 7
1 5 5 -1 5
-1 1 4 -1 4

i think that b[4, 2] must be 6 and b[3, 2] must be 8

Vokin Andrei e-mail: vok@sbor.ru