int[][] a = {
            {0,0,0,0,0,0,0},
            {0,1,1,1,0,1,0},
            {0,1,0,1,0,1,0},
            {0,1,0,1,0,1,0},
            {0,1,0,0,0,1,0},
            {0,1,1,1,1,1,0},
            {0,0,0,0,0,0,0}
        };