H, W = map(int, input().split())

T = 0
if H > W:
    H, W = W, H
    T = 1

ans = [["$" for _ in range(W)] for _ in range(H)]
if H == 1:
    for j in range(W):
        ans[0][j] = 'O' if j & 1 else 'X'
elif H % 2 == 0:
    p = 'O'
    q = 'X'
    for i in range(0, H, 2):
        for j in range(W):
            ans[i][j] = p if j & 1 else q
            ans[i + 1][j] = p if j & 1 else q
        p, q = q, p
else:
    p = 'O'
    q = 'X'
    for i in range(0, H - 1, 2):
        for j in range(W):
            ans[i][j] = p if j & 1 else q
            ans[i + 1][j] = p if j & 1 else q
        p, q = q, p
    
    for j in range(W):
        ans[H - 1][j] = p if j & 1 else q
    p, q = q, p

if T:
    for j in range(W):
        B = []
        for i in range(H):
            B.append(ans[i][j])
        print("".join(B))
else:
    for i in range(H):
        print("".join(ans[i]))