#include <iostream>
using namespace std;
int a=5;
void f() {
a=a+1;
cout << "a in f :" << a << " (" << &a << ")" << endl;
return;}
main() {
cout << "a in main:" << a << " (" << &a << ")" << endl;
f();
cout << "a in main:" << a << " (" << &a << ")" << endl;}