H, W = map(int, input().split())
ans = [['a'] * (W) for _ in range(H)]

for i in range(H):
    ii = (i//2)%2
    for j in range(W):
        jj = j%2
        if ii == jj:
            ans[i][j] = 'O'
        else:
            ans[i][j] = 'X'

for a in ans:
    print(''.join(a))