class Rational:
    
    def __init__(self,num,denom):
        self._numerator = num
        self._denominator = denom
        self.reduce()
    
    def add(self,f):
        num = self._numerator * f._denominator + f._numerator * self._denominator
        denom = self._denominator * f._denominator
        return Fraction(num,denom)
    
    def multiply(self, f):
        num = self._numerator * f._numerator
        denom = self._denominator * f._denominator
        return Fraction(num,denom)
    
    def subtract(self, f):
        num = self._numerator * f._denominator - f._numerator * self._denominator
        denom = self._denominator * f._denominator
        return Fraction(num,denom)
    
    def divide(self, f):
        num = self._numerator * f._denominator
        denom = self._denominator * f._numerator
        return Fraction(num,denom)
    
    def get_numerator(self):
        return self._numerator
    
    ##def set_numerator(self,n):
    ##    self._numerator = n
    
    def get_denominator(self):
        return self._denominator
        
    @staticmethod
    def gcd(m,n):
        while n != 0:
            r = m%n
            m = n
            n = r
        return m
    
    def reduce(self):
        g = Fraction.gcd(self._numerator,self._denominator)
        if g != 0:
            self._numerator = self._numerator / g
            self._denominator = self._denominator / g
        
        if self._denominator < 0:
            self._numerator = -self._numerator
            self._denominator = -self._denominator

    
    def __str__(self):
        if self._denominator == 1:
            return str(int(self._numerator))
        else:
            return str(int(self._numerator)) + "/" + str(int(self._denominator))

f1 = Rational(15.5,30)

print(f1)

31/60

f2 = Rational(40,1)

print(f2)

40