#include <iostream>
#include <cstdio>

using namespace std;

int main(){
    printf(
        "ABCDEFGHIJKLMNOPQR\n"
        "BABCDEFGHIJKLMNOPQ\n"
        "CBABCDEFGHIJKLMNOP\n"
        "DCBABCDEFGHIJKLMNO\n"
        "EDCBABCDEFGHIJKLMN\n"
        "FEDCBABCDEFGHIJKLM\n"
        "GFEDCBABCDEFGHIJKL\n"
        "HGFEDCBABCDEFGHIJK\n"
        "IHGFEDCBABCDEFGHIJ\n"
        "JIHGFEDCBABCDEFGHI"
    );
    return 0;
}