h, w = map(int, input().split())
a = [[0, 1, 1], [1, 0, 1], [1, 0, 1]]
res = [[-1]*w for _ in range(h)]
for i in range(h):
    for j in range(w):
        res[i][j] = a[i % 3][j % 3]
for i in range(h):
    for j in range(w):
        print("O" if res[i][j] else "X", end="")
    print()