class Rational(object):
    def __init__(self, p, q):
        self.p = p
        self.q = q
    def yuefen(self):
        n = self.p if self.p<self.q else self.q
        while n>1:
            if self.p%n==0 and self.q%n==0:
                self.p /=n
                self.q /=n
            n-=1
    def __add__(self, r):
        re = Rational(self.p * r.q + self.q * r.p, self.q * r.q)
        re.yuefen()
        return re
   
    def __sub__(self, r):
        re =Rational(self.p*r.q - self.q*r.p,self.q*r.q)
        re.yuefen()
        return re

    def __mul__(self, r):
        re=Rational(self.p*r.p,self.q*r.q)
        re.yuefen()
        return re
   
    def __div__(self, r):
        re=Rational(self.p*r.q,self.q*r.p)
        re.yuefen()
        return re

    def __str__(self):
        return '%s/%s'%(self.p,self.q)

    __repr__ = __str__

r1 = Rational(1, 2)
r2 = Rational(1, 4)
print r1 + r2
print r1 - r2
print r1 * r2
print r1 / r2