#include <iostream>

using namespace std;

int GCD(int a, int b)
{
    while (b)
    {
        a %= b;
        swap(a, b);
    }
    return a;
}

class Rational
{
public:
    Rational() : p(0), q(1)
    {}

    Rational(int numerator, int denominator) : p(numerator), q(denominator)
    {
        if (p > 0 && q < 0)
        {
            p = -p;
            q = -q;
        }

        if (p == 0)
            q = 1;

        int t = GCD(p, q);
        p /= t;
        q /= t;
    }

    int Numerator() const
    {
        return p;
    }

    int Denominator() const
    {
        return q;
    }

private:
    int p;
    int q;
};

bool operator==(const Rational &a, const Rational &b)
{
    return (a.Denominator() == b.Denominator() && a.Numerator() == b.Numerator());
}

Rational operator+(const Rational &a, const Rational &b)
{
    return Rational(a.Numerator() * b.Denominator() + b.Numerator() * a.Denominator(),
                    a.Denominator() * b.Denominator());
}

Rational operator-(const Rational &a, const Rational &b)
{
    return Rational(a.Numerator() * b.Denominator() - b.Numerator() * a.Denominator(),
                    a.Denominator() * b.Denominator());
}

void printRational(const Rational &r)
{
    cout << r.Numerator() << "/" << r.Denominator();
}

void testRational(int n1, int d1, int n2, int d2)
{
    Rational r1(n1, d1);
    Rational r2(n2, d2);
    printRational(r1);
    cout << " and ";
    printRational(r2);
    cout << "\nSum: ";
    printRational(r1 + r2);
    cout << " ";
    printRational(r2 + r1);
    cout << "\nDiff: ";
    printRational(r1 - r2);
    cout << " ";
    printRational(r2 - r1);
    cout << "\nEqu: " << (r1 == r2) << " = " << (r2 == r1) << endl << endl;
}

int main()
{
    testRational(1, 1, 1, 1);
    testRational(1, 1, 2, 2);
    testRational(2, 2, 2, 2);
    testRational(-1, -1, -1, -1);
    cout << endl;
    testRational(-1, 1, -2, 2);
    testRational(1, -1, 2, -2);
    testRational(-1, 1, 2, -2);

    testRational(0, -1, 2, -2);


}