#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; 
}