#include <iostream>
#include <cmath>


class Rational{
    int a, b;

    int nod(int t, int s) const {
            while (s) {
                t %= s;
                std::swap(t, s);
            }
            return abs(t);
    }

    void rev_com_div() {
        if (b < 0) {
            a *= -1;
            b *= -1;
        }
        int s = nod(a, b);
        a /= s;
        b /= s;
    }

public:
    Rational(int a = 0, int b = 1) : a(a), b(b)
    {
        rev_com_div();
    }

    Rational(Rational const& s) : a(s.a), b(s.b)
    {
        rev_com_div();
    }

    Rational & Add(Rational const& s) {
        a = a * s.b + b * s.a;
        b = b * s.b;
        rev_com_div();
        return *this;
    }

    Rational & Substract(Rational const& s) {
        a = a * s.b - b * s.a;
        b = b * s.b;
        rev_com_div();
        return *this;
    }

    Rational & Multiply(Rational const& s) {
        a *= s.a;
        b *= s.b;
        rev_com_div();
        return *this;
    }

    Rational & Divide(Rational const& s) {
        a *= s.b;
        b *= s.a;
        rev_com_div();
        return *this;
    }

    bool EqualTo(Rational const& s) const {
        return a == s.a && b == s.b;
    }

    int CompareTo(Rational const& s) const {
        int sum = a * s.b - s.a * b;
        return sum;
    }

    bool IsInteger() const {
        return b == 1;
    }

    std::string ToString() const {
        return std::to_string(a) + ":" + std::to_string(b);
    }

};