def lag(array, n=1):
    """
    >>> x = [19, 100, 36, 6, 100, 20, 75, 66, 98, 55]
    >>> lag(x)
    [100, 36, 6, 100, 20, 75, 66, 98, 55]
    >>> lag(x, 2)
    [36, 6, 100, 20, 75, 66, 98, 55]
    """
    return array[n:]