(a, b, A, B)
return n, d
Compute `M = a b - 1`, `e = A M + a`, `d = B M + b`, `n = (e d - 1) / M`.
    The *private key* is `d`, which Bob keeps secret.

    Examples
    ========

    >>> from sympy.crypto.crypto import kid_rsa_private_key
    >>> a, b, A, B = 3, 4, 5, 6
    >>> kid_rsa_private_key(a, b, A, B)
    (369, 70)
Compute `M = a b - 1`, `e = A M + a`, `d = B M + b`, `n = (e d - 1) / M`.
    The *private key* is `d`, which Bob keeps secret.
Compute M = a b - 1 e = A M + a d = B M + b n = ( e d - 1 ) / M . The * private key * is d which Bob keeps secret .
def kid_rsa_private_key(a, b, A, B):
    """
    Compute `M = a b - 1`, `e = A M + a`, `d = B M + b`, `n = (e d - 1) / M`.
    The *private key* is `d`, which Bob keeps secret.

    Examples
    ========

    >>> from sympy.crypto.crypto import kid_rsa_private_key
    >>> a, b, A, B = 3, 4, 5, 6
    >>> kid_rsa_private_key(a, b, A, B)
    (369, 70)

    """
    M = S(a*b - 1)
    e = S(A*M + a)
    d = S(B*M + b)
    n = S((e*d - 1)//M)
    return n, d
def kid_rsa_private_key ( a , b , A , B ) : M = S ( a * b - 1 ) e = S ( A * M + a ) d = S ( B * M + b ) n = S ( ( e * d - 1 ) // M ) return n , d