t = int(input())
ok = ["ooo", "-oo", "oo-", "-o--", "--o-"]
for i in range(500):
    ok.append("o" + "-" * (i * 2 + 1) + "o")
print(ok[:10])
for _ in range(t):
    n, s = input().split()
    n = int(n)
    f = False
    for i in ok:
        if i in s:
            print("O")
            f = True
            break
    if f:
        continue
    print("X")