#include <iostream>
using namespace std;

class Rational {
public:
    Rational() {
        // Реализуйте конструктор по умолчанию
        numer = 0;
        denom = 1;
    }

    Rational(int a, int b) {
        // Реализуйте конструктор
        int numerator, denominator, nod;
        numerator = a;
        denominator = b;
        a = abs(numerator);
        b = abs(denominator);

        while (a > 0 && b > 0) {
            if (a > b) {
                a %= b;
            }
            else {
                b %= a;
            }
        }
        nod = a + b;

        numer = numerator / nod;
        denom = denominator / nod;

        if (numer*denom < 0) {
            if (denom < 0)
                denom *= (-1);
            if (numer >= 0) {
                numer *= (-1);
            }

        }
        else {
            if (numer < 0) {
                numer *= (-1);
            }
            if (denom < 0) {
                denom *= (-1);
            }
        }


    }

    int Numerator() const {

        return numer;


    }

    int Denominator() const {

        return denom;
    }

private:
    // Добавьте поля
    int numer;
    int denom;
};
Rational operator+ ( Rational & left,  Rational&  right) {
    int denom_1, numer_1;
    denom_1 = left.Denominator()*right.Denominator();
    numer_1 = right.Numerator()*left.Denominator()+ right.Denominator()*left.Numerator();
    Rational answer(numer_1, denom_1);
    return answer;
}

Rational operator- (Rational & left, Rational&  right) {
    int denom_1, numer_1;
    denom_1 = left.Denominator()*right.Denominator();
    numer_1 = left.Numerator()*right.Denominator() -right.Numerator()*left.Denominator();
    Rational answer(numer_1, denom_1);
    return answer;
}

bool operator== ( const Rational& left,const  Rational&  right) {//left<right
    if ((left.Numerator() == right.Numerator()) && (left.Denominator() == right.Denominator())) {
        return true;
    }
    return false;
}

void printrational(const Rational & rational) {
    cout << rational.Numerator() << "/" << rational.Denominator()<<endl;
}
// Реализуйте для класса Rational операторы ==, + и -

int main() {
    {
        Rational r1(4, 6);
        Rational r2(2, 3);
        bool equal = r1 == r2;
        if (!equal) {
            cout << "4/6 != 2/3" << endl;
            return 1;
        }
    }

    {
        Rational a(2, 3);
        Rational b(4, 3);
        Rational c = a + b;
        bool equal = c == Rational(2, 1);
        if (!equal) {
            cout << "2/3 + 4/3 != 2" << endl;
            return 2;
        }
    }

    {
        Rational a(5, 7);
        Rational b(2, 9);
        Rational c = a - b;
        bool equal = c == Rational(31, 63);
        if (!equal) {
            cout << "5/7 - 2/9 != 31/63" << endl;
            return 3;
        }
    }


    cout << "OK" << endl;
    system("pause");
    return 0;
}