1 P3

     2 4 4

     3 15

     4  0  0  0    0  0  0    0  0  0   15  0 15

     5  0  0  0    0 15  7    0  0  0    0  0  0

     6  0  0  0    0  0  0    0 15  7    0  0  0

     7 15  0 15    0  0  0    0  0  0    0  0  0