def sum_prod_diags(matrix):

    n = len(matrix)
    psum =[1] * (2*n-1)
    pdif = {}


    n = len(matrix)
    for i in range(0, n ):
        for j in range(0, len(matrix[i])):
            dif = i-j
            if (dif in pdif):
                pdif[dif] *= matrix[i][j]
            else:
                pdif[dif] = matrix[i][j]
            psum[i+j] *= matrix[i][j]
    a = 0
    for i in range(0, len(psum)): a += psum[i]
    b = 0
    for key in pdif:
        b += pdif[key]
    return b-a