/*****************
备注：
*****************/
#include <iostream>
using namespace std;
#define LL long long
#define MAXM 3010
#define MAXN 3010
const int N =1e5+10;
const int INF =0x3f3f3f3f;
int main ()
{
    cout<<"A"<<endl;
    cout<<"AAA"<<endl;
    cout<<"AAAAA"<<endl;
    cout<<"AAAAAAA"<<endl;
   return 0;
}