def checkerd(first):
    current = ord(first)
    while True:
        yield chr(current)
        current^=21

W,H,C = input().split()
W,H = map(int,[W,H])
checkerd_pattern = []
first = C
for line in range(H):
    if line:
        first = chr(ord(checkerd_pattern[line - 1][0]) ^ 21)
    pattern = checkerd(first)
    checkerd_pattern.append([])
    for wide in range(W):
        checkerd_pattern[line].append(pattern.__next__())
for line in checkerd_pattern:
    print("".join(line))