#include <iostream>
using namespace std;
int main(){
     cout<<"ABCDEFGHIJKLMNOPQR"<<endl;
     cout<<"BABCDEFGHIJKLMNOPQ"<<endl;
     cout<<"CBABCDEFGHIJKLMNOP"<<endl;
     cout<<"DCBABCDEFGHIJKLMNO"<<endl;
     cout<<"EDCBABCDEFGHIJKLMN"<<endl;
     cout<<"FEDCBABCDEFGHIJKLM"<<endl;
     cout<<"GFEDCBABCDEFGHIJKL"<<endl;
     cout<<"HGFEDCBABCDEFGHIJK"<<endl;
     cout<<"IHGFEDCBABCDEFGHIJ"<<endl;
     cout<<"JIHGFEDCBABCDEFGHI"<<endl;
     return 0;
}