#include <iostream> 
using namespace std; 
 
void f(); // f's protoype 
 
int main() 
{ 
  cout << "In main()\n"; 
 
  f(); // call f() 
 
  cout << "Back in main()\n"; 
 
  return 0; 
} 
 
// This if the function's definition. 
void f() 
{ 
  cout << "Inside f()\n"; 
}
