7
 6  8  0  4  2  1  7
 4  2  0  1  0  0  0
 3  2  0  0  0  0
 0  0  0  0  0
 0  1  2  1
 1  1  0
 0  0
 1
 2  1  2  0  1  0  0
 5  1  2  0  0  0
 0  0  0  0  0
 2  0  0  1
 1  0  1
 1  0
 6