#include <iostream>

using namespace std;

class Fraction
{
	int nume, deno;
public:
	Fraction()	// 0/1
	{	nume = 0; deno = 1;   }
	Fraction(int n, int d)
	{	nume = n; deno = d;   }
	void Set(int n, int d) 
        {       nume = n; deno = d;   }
	void Print() const
	{	cout << nume << '/' << deno;   } 
	Fraction Mult(Fraction f)
	{	Fraction t;
		int n, d;
		n = nume*f.nume;
		d = deno*f.deno;
		t.Set(n, d);
		return t;
	}	
};

int main()
{	int n, d;
	Fraction x, y, z;
	char dummy, op;
	
	cout << "Input x (n/d, -1/1 to quit): ";
	cin >> n >> dummy >> d;	
	while( n!=-1 && d!=1 )
	{
		// Set x = n/d?
		x.Set(n, d);
		cout << "Input y (n/d): ";
        	cin >> n >> dummy >> d;
        	// Set y = n/d?
        	y.Set(n, d);
		cout << "Operation? (+, -, *, /) ";
		cin >> op;
		cout << "\n\n";
		if( op == '*')
			z = x.Mult(y);
		else  	cout << "I am woking on.\n\n";

		// DEbug - out?
		x.Print();	
		cout << " " << op << " ";	
        	y.Print();
        	cout << " = ";
                z.Print();
                cout << "\n";

		cout << "\n\n******************\nInput x (n/d, -1/1 to quit): ";
	        cin >> n >> dummy >> d; 
	}

	cout << "\n\nBye.\n\n";
	return 0;
}