def RecExpo(base, exp):
    """
    Recursively computes base^exp for nonnegative exponents and return the result

    Examples:
        >>> RecExpo(0,200)
        0
        >>> RecExpo(200,0)
        1
        >>> RecExpo(2,10)
        1024
        >>> RecExpo(10,4)
        10000
        >>> from math import pi, e
        >>> RecExpo(pi, 2)
        9.869604401089358
        >>> RecExpo(e, 50)
        5.18470552858706e+21

    """
    if exp == 0:
        return 1
    else:
        return RecExpo(base, exp-1) * base