Calc

import java.util.Scanner;

public class Calc {
    public static void main(String[] args) {

        int res = 0;
        System.out.println("старт");
        Scanner scan = new Scanner(System.in);
        System.out.println("число 1");
        int n1 = scan.nextInt();
        System.out.println("число 2");
        int n2 = scan.nextInt();
        System.out.println("знак");
        String op;
        op = scan.next();
        System.out.println(n1 + op + n2);
        switch (op) {
        case "+":
            res = n1 + n2;
            break;
        case "-":
            res = n1 - n2;
            break;
        case "*":
            res = n1 * n2;
            break;
        case "/":
            res = n1 / n2;
            break;
        default:
            System.out.println("default");
            break;
        }
        System.out.println("равно " + res);

    }

}