def del_constant_start_stop(x):
    """
    >>> l = [1,2,3,4]
    >>> del_constant_start_stop(l)
    [1, 2]

    >>> l = [1,2,3,4,5,6,7]
    >>> del_constant_start_stop(l)
    [1, 2, 7]
    """
    del x[2:6]
    return x