Matrix of Palindromes

rows, cols = map(int, input().split())

matrix = [[] for _ in range(rows)]

for x in range(97, 97 + rows):
    first_last_letter = chr(x)
    for y in range(x, cols + x):
        middle_letter = chr(y)
        word = f'{first_last_letter}{middle_letter}{first_last_letter}'
        matrix[x - 97].append(word)

[print(' '.join(x)) for x in matrix]