import java.util.Objects;
import java.util.Scanner;
//import java.util.

public class Main {
    public static void main(String[] args) {
        start:
        //1 naujas dalykas - break su label
        {
            double no1 = 0;
            double no2 = 0;
            double result;
            String[] symbols = {"*", "/", "+", "-"}; //2 naujas dalykas String array
            char sym;
            String yesno;

            System.out.println("Incomplete calculator");
            System.out.println("Enter the first number");
            Scanner input1 = new Scanner(System.in);
            no1 = input1.nextDouble();
            System.out.println("Enter the second number");
            Scanner input2 = new Scanner(System.in);
            no2 = input2.nextDouble();
            System.out.println("Enter what operation you want to do (+; -; *; /)");
            Scanner input3 = new Scanner(System.in);
            sym = input3.next().charAt(0);

            if (sym.equals(symbols)) {
                System.out.println("Illegal operation");
                break start;
            } else
            if (no2 == 0) {
                break start;
            } else if (Objects.equals(sym, "+")) {
                result = no1 + no2;
                System.out.println(result);

                System.out.println("Do you want to keep calculating?");
                Scanner input4 = new Scanner(System.in);
                yesno = input4.nextLine();
                if (yesno == "yes") {
                    break start;
                } else ;

            }
        }
    }
}