#include <iostream>

#include <vector>

#include <algorithm>

using namespace std;

​

int main() {

  int a = 10, b = 25;

  cout << "Before: a = " << a << " | b = " << b << "\n";

  swap(a, b);

  cout << "After:  a = " << a << " | b = " << b << "\n";

  return 0;

}

​