//C program
//Swap two numbers
//NO Extra Space
#include <stdio.h>
int main() 
{
    int x=90;
    int y=89;
    printf("x : %d , y: %d\n",x,y);
    //Code to swap two numbers
    x=x+y;
    y=x-y;
    x=x-y;
    printf("x : %d , y: %d\n",x,y);
    return 0;
}