#include <iostream>
using namespace std;
class Node {
  public:
    Node() {
    
    }
    virtual void f1() = 0;
    virtual int compareTo(Node *n) = 0;
};
class MyNode1 : public Node {
  public:
    MyNode1() {
       
    }
    void f1() {
      cout << "MyNode1 \n";
    }
    int compareTo(Node *n) {
      return 0;
    }
};
class MyNode2 : public Node {
  public:
    MyNode2(): Node() {
      
    }
    void f1() {
      cout << "MyNode2\n";
    }
    int compareTo(Node *n) {
      return 0;
    }
};
int main() {
  Node *nodes[2];
  nodes[0] = new MyNode1();
  nodes[1] = new MyNode2();
  for (int i = 0;i < 2;i++) {
    cout << nodes[i]->compareTo(nodes[i]) << "\n";
    nodes[i]->f1();
  }
  return 0;
}