#include <iostream> 
#include <stdlib.h> 
 
using namespace std; 
 
class A 
{ 
public: 
    void f() 
    { 
        cout << "A::f()"; 
    } 
}; 
 
class B 
{ 
public: 
    void f() 
    { 
        cout << "B::f()"; 
    } 
}; 
  
#define A B  
  
int main()  {  
 
    A a; 
    a.f(); 
    return 0; 
}