#include <iostream>

using namespace std;

void swap(int &arg1, int &arg2)
{
   int temp = arg1;
   arg1 = arg2;
   arg2 = temp;
}

int main (int argc, char *argv[]) {
   cout << "Hello World! in c++" << endl;

   int foo = 42;
   int foo2 = 11;

   cout << "foo  - " << foo << " " << foo2 << endl;
   
   swap(foo, foo2);

   cout << "foo  - " << foo << " " << foo2 << endl;
}