def max_recursion(tup):
    """
    Returns the largest element in the tuple.

    >>> max_recursion((1,2,3,4))
    4
    >>> max_recursion((13,2,3,4))
    13
    >>> max_recursion((13,2,33,4))
    33
    """
    if len(tup) == 1:
        return tup[0]
    return tup[0] if tup[0] > max_recursion(tup[1:]) else max_recursion(tup[1:])