#include<bits/stdc++.h>
using namespace std;
int main(){
	cout<<"ABCDEFGHIJKLMNOPQR\nBABCDEFGHIJKLMNOPQ\nCBABCDEFGHIJKLMNOP\nDCBABCDEFGHIJKLMNO\nEDCBABCDEFGHIJKLMN\nFEDCBABCDEFGHIJKLM\nGFEDCBABCDEFGHIJKL\nHGFEDCBABCDEFGHIJK\nIHGFEDCBABCDEFGHIJ\nJIHGFEDCBABCDEFGHI\n";

	return 0;
}