WAP in C to Addition without using third variable

1. #include<stdio.h>
2. 
   
3. void main()
4. {
5.    int a,b,;
6.    printf("Enter the Frist no. = ");
7.    scanf("%d", &a);
8.    printf("Enter the Frist no. = ");
9.    scanf("%d", &b);
10.    
11.    a = a + b ;
12.  
13.    printf("Sum of the Number = %d",a);
14.  
15.    return 0;
16. }