#include <iostream>

using namespace std;

namespace Calculations {
    class Rational {
    private:
        int numerator;
        int denominator;

        int gcm(int, int) const;
        int lcm(int, int) const;

    public:
        Rational(int ,int );

        Rational(int);

        friend ostream &operator<<(ostream &, const Rational &);

        friend istream &operator>>(istream &, Rational &);

        int getNumerator() const;

        int getDenominator() const;

        friend Rational operator+(const Rational &, const Rational &);

        friend Rational operator-(const Rational &, const Rational &);

        friend Rational operator*(const Rational &, const Rational &);

        friend Rational operator/(const Rational &, const Rational &);

        friend Rational operator-(const Rational &);

        friend Rational operator!(const Rational &);

//        friend double static_cast<double>(liczba_starego_typu)
    };
}