#include <iostream>
using namespace std;
class A
{ protected: int x;
public: A(int i):x(i){}
int get_x(){ return x; } };
class B: A
{ protected: int y;
public: B(int i,int j):y(i),A(j){}
int get_y(){ return get_x()+y; } };
class C: protected B
{ protected: int z;
public: C(int i,int j,int k):z(i),B(j,k){}
int get_z(){ return get_x()+get_y()+z; } };
int main()
{ C c(5,6,7);
cout<<c.get_z();
return 0;
}