import timeit


def intersect_list(n):
    """Measure the run time for intersecting two lists.
    """
    list_a = range(n)
    list_b = range(n-3, 2 * n)
    start = timeit.default_timer()
    in_both = []
    for x in list_a:
        if x in list_b:
            in_both.append(x)
    run_time = timeit.default_timer() - start
    return run_time, in_both