c

    40     0   -10   -10     0     0     0   -10   -30
    60     0   -20   -20     0     0    10   -10   -50
    60   -10   -20   -10     0     0    20   -10   -60
    50   -20   -20   -10     0     0    30     0   -60
    40   -20   -10    10     0   -10    30     0   -60
    30   -10     0    10     0   -10    20     0   -50
    30     0    10     0   -10   -10    20    10   -50
    30   -10    20   -10   -20    10    10    10   -40
    20   -10    20   -10   -20    10    10    10   -30