def lv_unpack(txt):
    """
    Deserializes a string of the length:value format

    :param txt: The input string
    :return: a list og values
    """
    txt = txt.strip()
    res = []
    while txt:
        l, v = txt.split(":", 1)
        res.append(v[: int(l)])
        txt = v[int(l):]
    return res