Swap four variables without using fifth variables !!

Problem statement: Swap four variables without using fifth variables !!

Problem solving: 

1. public class SwapFourNumberWithoutFifthVariable {
2. public static void main(String[] args) {
3. int a = 10;
4. int b = 20;
5. int c = 30;
6. int d = 40;
7. 
   
8. a = a + b + c + d;
9. b = a - (b + c + d);
10. c = a - (b + c + d);
11. d = a - (b + c + d);
12. a = a - (b + c + d);
13. System.out.println("after swap value of a: " + a);
14. System.out.println("after swap value of b: " + b);
15. System.out.println("after swap value of c: " + c);
16. System.out.println("after swap value of d: " + d);
17. }
18. }

Output:

after swap value of a: 40

after swap value of b: 10

after swap value of c: 20

after swap value of d: 30