#include <iostream>
using namespace std;
void increment(int m){ // alias int m = a; 
  m++;
  cout << " m is " << m << "\n";
}

int main(){ 
  int a = 0;
  cout << " a is " << a << "\n"; // output: a is 0
  increment(a);                 // output: m is 1 
  cout << " a is " << a << "\n"; // output: a is 0
  return 0; 
}