lolcalc.py

class Value (Exception):
    def __init__ (self, vl):
        self._vl = vl
    def __int__ (self):
        return self._vl

def add (a, b):
    raise Value(a + b)

def mul (a, b):
    raise Value(a * b)


a = 2
b = 2

try:
    add (a, b)
except Value as rs:
    try:
        mul (int(rs), b)
    except Value as rs2:
        print (int (rs2))