h,w=map(int,input().split())
cnt = 0
ans = [["X"]*w for _ in range(h)]
for i in range(h):
    cnt = 0
    for j in range(w):
        if i%2 == 0:
            if cnt%4 == 0 or cnt%4 == 1:
                ans[i][j]="O"
        else:
            if cnt%4 == 2 or cnt%4 == 3:
                ans[i][j]="O"
        cnt += 1
for i in range(h):
    for j in range(w):
        print(ans[i][j],end="")
    print()