def build_row(i, size):
    left = [chr(96 + size - k) for k in range(i + 1)]
    right = [chr(96 + size - k) for k in range(i - 1, -1, -1)]
    return "-".join(left + right).center(size * 4 - 3, "-")

size = int(input())
rows = [build_row(i, size) for i in range(size)]
print("\n".join(rows + rows[-2::-1]))