Swapping Without Third Variable

import java.util.Scanner;
class SwappingNoThird
    {
        public static void  main(String san[])
    {
        int firstNumber,secondNumber;
        Scanner in=new Scanner(System.in);
   
        System.out.println("Enter the first number:");
        firstNumber=in.nextInt();
   
        System.out.println("Enter the second Number :");
        secondNumber=in.nextInt();
   
        System.out.println("Before Swapping two variables  FirstNumber : "  +firstNumber +" Second Number " +secondNumber);
       
        firstNumber=firstNumber+secondNumber;
        secondNumber=firstNumber-secondNumber;
        firstNumber=firstNumber-secondNumber;
       
   
        System.out.println("After  Swapping two variables  FirstNumber : "  +firstNumber +" Second Number " +secondNumber);
    }
    }

OUTPUT:

Enter the first number:
76
Enter the second Number :
67
Before Swapping two variables  FirstNumber : 76 Second Number 67
After  Swapping two variables  FirstNumber : 67 Second Number 76