How to swap two numbers without using temporary variable

Write a program to swap or exchange two numbers. You should not use any temporary or third variable to swap.

Program

package com.scanftree.algos;
public class MySwapingTwoNumbers {
	public static void main(String a[]) {
		int x = 10;
		int y = 20;
		System.out.println("Before swap:");
		System.out.println("x value: "+x);
		System.out.println("y value: "+y);
		x = x+y;
		y=x-y;
		x=x-y;
		System.out.println("After swap:");
		System.out.println("x value: "+x);
		System.out.println("y value: "+y);
	}
}

OutPut

Before swap:
x value: 10
y value: 20
After swap:
x value: 20
y value: 10