#include <iostream>
#include <algorithm>
using namespace std;

class Rational {
public:
    Rational() {
        // Реализуйте конструктор по умолчанию
        p=0;
        q=1;
		//для отладки
        //cout << "Hi, I am a Default Counstructor" << endl;
    }

    Rational(int numerator, int denominator) {
        // Реализуйте конструктор
	 if (numerator==0) {
 		p=0;
 		q=1;
 	} else {
 		int s = FindSign(numerator, denominator);
 		int nod=FindNod(numerator,denominator);
 		numerator=abs(numerator);
 		denominator=abs(denominator);
 		p=numerator/nod;
 		q=denominator/nod;

 		p=p*s;
 	}
	//для отладки
 	//cout << p << "/" << q << endl;
    }

    int Numerator() const {
        // Реализуйте этот метод
        return p;
    }

    int Denominator() const {
        // Реализуйте этот метод
        return q;
    }

private:
    // Добавьте поля
    int p, q;

int FindNod (int a, int b) {
    	int nod=1;
    	int i = 1;
    	while(i!=0) {
      	i=(a % b);
      	nod=b;
      	a=b;
      	b=i;
  }
  return nod;
}

int FindSign (int c, int d) {
  int mult = c*d;
  if (mult >=0) {
    return 1;
  } else {
    return -1;
  }
}

};

bool operator == (const Rational r1, const Rational r2) {
	if (r1.Numerator()==r2.Numerator ()&& r1.Denominator()==r2.Denominator()) {
	return  1;
} else {
	return 0;
}
}

Rational operator + (const Rational r1, const Rational r2) {
	if (r1.Denominator()==r2.Denominator()) {
		return Rational(r1.Numerator()+r2.Numerator(), r1.Denominator());
	} else {
		return Rational(r1.Numerator()*r2.Denominator() + r2.Numerator()*r1.Denominator(), r1.Denominator()*r2.Denominator());

	}
}

Rational operator - (const Rational r1, const Rational r2) {
	if (r1.Denominator()==r2.Denominator()) {
		return Rational (r1.Numerator()-r2.Numerator(), r1.Denominator());
	} else {
		return Rational (r1.Numerator()*r2.Denominator()-r2.Numerator()*r1.Denominator(), r1.Denominator()*r2.Denominator());
	}
}



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;
    return 0;
}