class utilities(object):
    def gcd(a, b):
        hi = max(abs(a), abs(b))
        lo = min(abs(a), abs(b))
        div = lo
        while not (hi % div == 0 and lo % div == 0):
            div -= 1
        return div
    gcd = staticmethod(gcd)

class fraction(object):
    def __init__(self, num, den):
        self.num = num / utilities.gcd(num, den)
        self.den = den / utilities.gcd(num, den)
    def __str__(self):
        return str(self.num) + "/" + str(self.den)
    def add(self, other):
        return fraction(self.num * other.den + self.den * other.num, self.den * other.den)

def sum(a, b):
    return fraction(a.num * b.den + a.den * b.num, a.den * b.den)