#include "iostream"
using namespace std;

class CMyExcept
{
    void writeout(){cout<<"XXX\n";}
};

class CExcept0: public CMyExcept
{
public: void  writeout(){cout<<"AAA\n";}
};

class CExcept1: public CExcept0
{
public: void writeout(){cout<<"BBB\n";}
};

class CExcept2: public CExcept1
{
public: void writeout(){cout<<"CCC\n";}
};


void main()
{

    char ch;
    try{
        cin>>ch;
        switch(ch)
        {
        case '0': throw CExcept0();
        case '1': throw CExcept1();
        case '2': throw CExcept2();
        }
    }
    catch(CExcept0)
    {
        cout<<'A'<<endl;
        CExcept0 a;
        a.writeout();
    }
    catch(CExcept1)
    {
        cout<<'B'<<endl;
        CExcept1 b;
        b.writeout();
    }
    catch(CExcept2)
    {
        cout<<'C'<<endl;
        CExcept2 c;
        c.writeout();
    }
}