#include <stdio.h>

void something(int* a, int* b) {
  int tmp = *a;
  *a = *b;
  *b = tmp;
}

int main() {
  int x = 1;
  int y = 2;
  something(&x, &y);
  printf("x = %d, y = %d\n", x, y);
  return 0;
}