// How to use the scope operator to resolve the ambiguity.

#include <iostream>
#include <string>

using namespace std;

class A {
public:
  int data;

  int operation(){
     cout << "A: operation" << endl;
     return data;
  }
};

class B {
public:
  int data;

  int operation(){
     cout << "B: operation" << endl;
     return data;
  }
};

class C: public A, public B{
};

int f(C* c){
   int r1 = c->A::operation(),
       r2 = c->B::operation();
   return r1 + r2;     
}


int main(){
  f(new C());   // OUTPUT:
                // A: operation
                // B: operation
}