S = [
        [0,1,0,0,7,8,0,0,0],
        [0,8,0,0,4,0,9,0,0],
        [0,0,5,6,0,0,0,1,0],
        [1,0,0,0,6,0,0,0,5],
        [0,4,0,9,1,5,0,7,2],
        [0,6,7,0,8,0,4,0,0],
        [0,0,0,3,0,0,1,0,0],
        [0,7,0,8,9,0,0,2,3],
        [0,0,0,0,0,4,0,0,0]
]