Java : Program swapping two numbers without using third variable

public class SwapTwoNo {

    /**
     * @param args
     */
        public static  void swap(int a , int b){
           
            a = b+a;
            b = a-b;
            a = a-b;
           
            System.out.println("Values of a and b after swap := " + a +"  "+ b + " respectively");
        }   

   
        public static void main(String[] args) {
           
            int a = 5;
            int b = 6;
            System.out.println("Values of a and b before swap := " + a +"  "+ b + " respectively");
            swap(a,b);
           
        }
}