matrix field=25 rows=15 cols=15
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  0  0  0  0  0  1  0  0  0  0  0  0  0  0  0
  1  0  4  0  1  0  0  0  0  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  1  0  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  1  0  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  1  0  0  0  0
  0  0  0  0  0  0  0  0  0  0  0  0  1  0  0
 22 19 20  5 19 10 21 12 17 21 24  6 23 23  0
  0  0  0  0  0  0  0  0  0  0  0  0  0  0  1
 16 21 22 10 16  5  9 19 22  3 22 14  3 23 16
  0  0  0  1  0  0  0  0  0  0  0  0  0  0  0
  8  2  7  1  0 13 17 14  8 15  6 11 15  4  9
 20  6 13 22 13 14 14 10  7  1 24  1  0 17 20