#!/usr/bin/env python
#
# Fraction class Version 0.1
# Author:  Yotam Medini  yotam.medini@gmail.com -- Created: 2006/June/01

import sys


class Frac:

    def __init__(self, n=0, d=1):
        self.n = n # Numerator
        self.d = d # Denominator


    def __str__(self):
        return "%d/%d" % (self.n, self.d)


def add(a, b):
    add_numerator = a.n * b.d + b.n * a.d
    add_denominator = a.d * b.d
    total = Frac(add_numerator, add_denominator)
    return total


def test_add(a, b):
    sys.stdout.write("%s + %s = %s\n" % (a, b, add(a, b)))


# Main
three_fifths = Frac(3, 5)
two_sevenths = Frac(2, 7)
one = Frac(1)
zero = Frac()

test_add(three_fifths, two_sevenths)
test_add(three_fifths, one)
test_add(two_sevenths, zero)
test_add(zero, one)
sys.exit(0)