Hello,

I tried to create a graph for this problem in this way:
Vertices correspond to intersections of the board (left upper (0; 0) and right lower (n; m)).
I will denote the vertice by [i][j][l]. If i = 0, then we have face of the cloath, else if i = 1, we have the rear of the cloth. j means the row, and l - column.

For the example test, graph edges:
[0][1][1] <-> [1][2][2]
[0][2][2] <-> [1][1][1]
[0][2][2] <-> [1][3][3]
[0][3][3] <-> [1][2][2]
[1][2][1] <-> [0][3][2]
[1][2][2] <-> [0][3][3]
[1][2][3] <-> [0][3][2]
[1][2][5] <-> [0][1][4]
[1][3][2] <-> [0][2][1]
[1][3][2] <-> [0][2][3]
[1][3][3] <-> [0][2][2]

I can not count degrees correctly with this graph even for the example test. Is there a better graph representation? If no, how to solve the problem with this one?