def gf_crt(U, M, K=None):
    """
    Chinese Remainder Theorem.

    Given a set of integer residues ``u_0,...,u_n`` and a set of
    co-prime integer moduli ``m_0,...,m_n``, returns an integer
    ``u``, such that ``u = u_i mod m_i`` for ``i = ``0,...,n``.

    As an example consider a set of residues ``U = [49, 76, 65]``
    and a set of moduli ``M = [99, 97, 95]``. Then we have::

       >>> from sympy.polys.domains import ZZ
       >>> from sympy.polys.galoistools import gf_crt
       >>> from sympy.ntheory.modular import solve_congruence

       >>> gf_crt([49, 76, 65], [99, 97, 95], ZZ)
       639985

    This is the correct result because::

       >>> [639985 % m for m in [99, 97, 95]]
       [49, 76, 65]

    Note: this is a low-level routine with no error checking.

    See Also
    ========

    sympy.ntheory.modular.crt : a higher level crt routine
    sympy.ntheory.modular.solve_congruence

    """
    p = prod(M, start=K.one)
    v = K.zero

    for u, m in zip(U, M):
        e = p // m
        s, _, _ = K.gcdex(e, m)
        v += e*(u*m % s)

    return v % p
dataset/ETHPy150Open sympy/sympy/sympy/polys/galoistools.py/gf_crt/swapped operands of `%`