#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;
}