How to learn C language in easy way

WAP TO PRINT SUM OPERATION WITHOUT USING THIRD VARIABLE

#include<stdio.h>
void main()
{
int a,b;
clrscr();
printf("enter the value of a=");
scanf("%d",&a);
printf("enter the value of b=");
scanf("%d",&b);
printf("SUM=%d",a+b); // Sum operation without using third variable
getch();
}
o/P:- enter the value of a= 4
      enter the value of b= 6
       
      SUM is = 10