#include <iostream>
#include <cstdlib>

using namespace std;

void swap(int &x, int &y) {
  int tmp = x;
  x = y;
  y = tmp;
}

int main(int argc, char **argv) {
  int a = 5, b = 10;

  swap(a, b);
  cout << "a: " << a << "; b: " << b << endl;
  return EXIT_SUCCESS;
}