#include <iostream>
using namespace std;

class ForbiddenFruit
{
public:
  ForbiddenFruit()
  {
    this->m_State = 0;
    this->showState();
  }
  ForbiddenFruit &operator()()
  {
    this->m_State = 1 - this->m_State;
    this->showState();
    return *this;
  }
private:
  int m_State;
  void showState()
  {
    cout << ((this->m_State) ? "B" : "A") << endl;
  }
};

int main(void)
{
  ForbiddenFruit flandre;
  
  flandre()()()()();
  
  return 0;
}