#include <iostream>
using namespace std;

class ABase {
public:
    void f(int i) const { cout << 1;}
    void f(char ch) const { cout << 2; }
};

class BBase {
public:
    void f(double d) const { cout << 3;}
};

class ABBase : public ABase, public BBase {
public:
    using ABase::f;
    using BBase::f;        
    void f(char ch) const { cout << 4; }
};

void g(ABBase& ab) {
    ab.f('c');
    ab.f(2.5);
    ab.f(4);
}

int main() {
    ABBase ab;
    g(ab);
}