h, w = map(int, input().split())

ans = []
for i in range(h):
    if i % 2 == 0:
        row = "O" * 2 + "X" * 2
    else:
        row = "X" * 2 + "O" * 2
    ans.append((row * ((w + 3) // 4))[:w])

print("\n".join(ans))