#include <iostream>

using namespace std;

// ^ we have to include <iostream> here because ostreams are defined in it

class rational {
    public:
        // this constructor is called for both rational() and rational(int, int)
        rational( int t = 0, int b = 1 ): top( t ), bottom( b ) { }
        
        // copy contructor
        rational( const rational & r ): top( r.top ), bottom( r.bottom ) { }
        
        // these are normal accessor methods
        int numerator( ) const { return top; }
        int denominator( ) const { return bottom; }
        
        // this operator is overloaded as a member function
        // note that it only needs one parameter, as the other
        // rational being added is *this
        const rational operator+ ( const rational & r) const;
        
        // this is (has to be) a global function, rather than
        // a member function. since the function uses private
        // variables directly it must be declared as a friend
        // to the class
        friend ostream& operator<< ( ostream & out, const rational & r);
    
    private:
        // private variables. no great surprise
        int top;
        int bottom;
};