A:=[[ 2, 1, 5, 4,-3, 6,-7],
    [ 1, 2,-7, 4,-6, 5, 3],
    [ 6,-5, 1, 4, 7,-3,-2],
    [ 2,-5,-4, 6, 1, 3, 7],
    [-7, 3, 5,-6, 1,-4, 2],
    [-5, 2, 6, 3, 7, 4,-1]]: