#include <stdio.h>

#include <stdlib.h>  // EXIT_SUCCESS



void swap(int *a, int *b) {

  int tmp = *a;

  *a = *b;

  *b = tmp;

}



int main(int argc, char **argv) {

  int a = 42, b = -7;



  swap(&a, &b);

  printf("a: %d, b: %d\n", a, b);

  return EXIT_SUCCESS;

}