#include<bits/stdc++.h>
using namespace std;
int main(){
cout<<"ABCDEFGHIJKLMNOPQR"<<'\n';
cout<<"BABCDEFGHIJKLMNOPQ"<<'\n';
cout<<"CBABCDEFGHIJKLMNOP"<<'\n';
cout<<"DCBABCDEFGHIJKLMNO"<<'\n';
cout<<"EDCBABCDEFGHIJKLMN"<<'\n';
cout<<"FEDCBABCDEFGHIJKLM"<<'\n';
cout<<"GFEDCBABCDEFGHIJKL"<<'\n';
cout<<"HGFEDCBABCDEFGHIJK"<<'\n';
cout<<"IHGFEDCBABCDEFGHIJ"<<'\n';
cout<<"JIHGFEDCBABCDEFGHI"<<'\n';
return 0;
}