第一周

package exception;

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        Fraction a = new Fraction(in.nextInt(), in.nextInt());
        Fraction b = new Fraction(in.nextInt(), in.nextInt());
        a.print();
        b.print();
        a.plus(b).print();
        a.multiply(b).plus(new Fraction(5, 6)).print();
        a.print();
        b.print();
        in.close();
    }
}

class Fraction {
    private int num1;
    private int num2;
    Fraction(int num1, int num2) {
        this.num1 = num1;
        this.num2 = num2;
    }
    double toDouble() {
        return (double) num1 / num2;
    }
    public Fraction plus(Fraction r) {
        Fraction pn = new Fraction(0, 1);
        pn.num1 = num1 * r.num2 + num2 * r.num1;
        pn.num2 = num2 * r.num2;
        return pn;
    }
     public Fraction multiply(Fraction r) {
        Fraction mn = new Fraction(0, 1);
        mn.num1 = num1 * r.num1;
        mn.num2 = num2 * r.num2;
        return mn;
    }
    void print() {
        int r, x = num2, y = num1;
        while (y != 0) {
            r = x % y;
            x = y;
            y = r;
        }
        num2 /= x;
        num1 /= x;
        if (num1 == num2) {
            System.out.println(num1 / num2);
        } else {
            System.out.println(num1 + "/" + num2);
        }
    }
}