print("""ABCDEFGHIJKLMNOPQR
BABCDEFGHIJKLMNOPQ
CBABCDEFGHIJKLMNOP
DCBABCDEFGHIJKLMNO
EDCBABCDEFGHIJKLMN
FEDCBABCDEFGHIJKLM
GFEDCBABCDEFGHIJKL
HGFEDCBABCDEFGHIJK
IHGFEDCBABCDEFGHIJ
JIHGFEDCBABCDEFGHI""")