package PTA;

import java.util.Scanner;

//201621123040林俊伟

public class Rational {
	
	private int v1;
	private int v2;
	
	//无参构造函数
	public Rational(){
		
	}
	
	//有参构造函数
	public Rational(int v1, int v2){
		this.v1 = v1;
		this.v2 = v2;
	}
	
	public int getV1() {
		return v1;
	}

	public void setV1(int v1) {
		this.v1 = v1;
	}

	public int getV2() {
		return v2;
	}

	public void setV2(int v2) {
		this.v2 = v2;
	}

	//约分
	public int Simplify(int m,int n){
		int t;
		while(m%n!=0)
		{
			t=n;
			n=m%n;
			m=t;
		}
		return n;
	}
	//加法
	public String Add(Rational a1,Rational a2){	
		int t;
		Rational R = new Rational();
		R.v2 = a1.v2*a2.v2;
		R.v1 = a1.v1*a2.v2+a2.v1*a1.v2;
		t=R.Simplify(R.v1, R.v2);
		R.v2/=t;
		R.v1/=t;
		return R.v1+"/"+R.v2;
	}
	//乘法
	public String Multiply(Rational a1,Rational a2){	
		Rational R = new Rational();
		R.v2 = a1.v2*a2.v2;
		R.v1 = a1.v1*a2.v1;
		int t = R.Simplify(R.v1, R.v2);
		R.v2/=t;
		R.v1/=t;
		return R.v1+"/"+R.v2;
	}
	//减法
	public String Subtract(Rational a1,Rational a2){	
		int t;
		Rational R = new Rational();
		R.v2 = a1.v2*a2.v2;
		R.v1 = a1.v1*a2.v2-a2.v1*a1.v2;
		t=R.Simplify(R.v1, R.v2);
		R.v2/=t;
		R.v1/=t;
		return R.v1+"/"+R.v2;
	}
	//除法
	public String Divide(Rational a1,Rational a2){	
		Rational R = new Rational();
		R.v2 = a1.v2*a2.v1;
		R.v1 = a1.v1*a2.v2;
		int t = R.Simplify(R.v1, R.v2);
		R.v2/=t;
		R.v1/=t;
		return R.v1+"/"+R.v2;
	}
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner in = new Scanner(System.in);
		Rational a = new Rational();
		Rational a1 = new Rational(in.nextInt(),in.nextInt());
		Rational a2 = new Rational(in.nextInt(),in.nextInt());
		String S = in.next();
			switch (S) {
			case "1"://加法
				System.out.println(a.Add(a1, a2));
				S = in.next();
				break;
            case "2"://减法
				System.out.println(a.Subtract(a1, a2));
				S = in.next();
				break;
            case "3"://乘法
				System.out.println(a.Multiply(a1, a2));
				S = in.next();
				break;
            case "4"://除法
				System.out.println(a.Divide(a1, a2));
				S = in.next();
				break;
			default:
				System.out.println("exit");
				break;
			}
	}
	}