Вход и изход от конзолата 4

import org.omg.CORBA.MARSHAL;
import org.omg.Messaging.SYNC_WITH_TRANSPORT;

import java.lang.reflect.Array;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner=new Scanner (System.in);

        int firstNum=Integer.parseInt(scanner.nextLine());
        int secondNum=Integer.parseInt(scanner.nextLine());

        firstNum=firstNum-secondNum;
        secondNum=firstNum+secondNum;
        firstNum=secondNum-firstNum;

        System.out.println(firstNum);

    }
}