import itertools


def interleave_lists(a, b):
    """
    Interleaves the values of two lists. The length is equal to the shorter of the two lists x 2

    :param a: first list e.g., ['a', 'b', 'c', 'd', 'e']
    :param b: second list e.g., [1, 2, 3]
    :return: interleaved list ['a', 1, 'b', 2, 'c', 3]
    """
    return list(itertools.chain(*zip(a, b)))