def gf_TC(f, K):
    """
    Return trailing coefficient of ``f``.

    **Examples**

    >>> from sympy.polys.domains import ZZ
    >>> from sympy.polys.galoistools import gf_TC

    >>> gf_TC([3, 0, 1], ZZ)
    1

    """
    if not f:
        return K.zero
    else:
        return f[-1]