#include <bits/stdc++.h>
#define endl codeforces
#define ALL(v) std::begin(v), std::end(v)
#define ALLR(v) std::rbegin(v), std::rend(v)
using ll = std::int64_t;
using ull = std::uint64_t;
using pii = std::pair<int, int>;
using tii = std::tuple<int, int, int>;
using pll = std::pair<ll, ll>;
using tll = std::tuple<ll, ll, ll>;
template <typename T> using vec = std::vector<T>;
template <typename T> using vvec = vec<vec<T>>;
template <typename T> const T& var_min(const T &t) { return t; }
template <typename T> const T& var_max(const T &t) { return t; }
template <typename T, typename... Tail> const T& var_min(const T &t, const Tail&... tail) { return std::min(t, var_min(tail...)); }
template <typename T, typename... Tail> const T& var_max(const T &t, const Tail&... tail) { return std::max(t, var_max(tail...)); }
template <typename T, typename... Tail> void chmin(T &t, const Tail&... tail) { t = var_min(t, tail...); }
template <typename T, typename... Tail> void chmax(T &t, const Tail&... tail) { t = var_max(t, tail...); }
template <typename T> const T& clamp(const T &t, const T &low, const T &high) { return std::max(low, std::min(high, t)); }
template <typename T> void chclamp(T &t, const T &low, const T &high) { return t = clamp(t, low, high); }
template <typename T> T make_v(T init) { return init; }
template <typename T, typename... Tail> auto make_v(T init, std::size_t s, Tail... tail) { auto v = std::move(make_v(init, tail...)); return vec<decltype(v)>(s, v); }
template <typename T, std::size_t Head, std::size_t ...Tail> struct multi_dem_array { using type = std::array<typename multi_dem_array<T, Tail...>::type, Head>; };
template <typename T, std::size_t Head> struct multi_dem_array<T, Head> { using type = std::array<T, Head>; };
template <typename T, std::size_t ...Args> using mdarray = typename multi_dem_array<T, Args...>::type;
namespace init__ { struct InitIO { InitIO() { std::cin.tie(nullptr); std::ios_base::sync_with_stdio(false); std::cout << std::fixed << std::setprecision(30); } } init_io; }

bool solve() {
    ll n;
    std::string s;
    std::cin >> n >> s;

    auto valid = [&](ll i) { return 0 <= i && i < n; };

    auto check = [&](ll l, ll r, const std::string &ss) {
        if (!valid(l)) return false;
        if (!valid(r - 1)) return false;
        return s.substr(l, r - l) == ss;
    };

    for (ll i = 0; i + 3 < s.size(); i++) if (check(i, i + 3, "ooo")) return true;
    for (ll i = 0; i < s.size(); i++) {
        if (s[i] != '-') continue;
        s[i] = 'o';
        for (ll j = -4; j <= 4; j++) if (check(i + j, i + j + 4, "-oo-")) return true;
        for (ll j = -3; j <= 3; j++) if (check(i + j, i + j + 3, "ooo")) return true;
        s[i] = '-';
    }
    for (ll i = 0; i < s.size(); i++) {
        if (s[i] != 'o') continue;
        ll l = i;
        ll r = i + 1;
        bool ok = false;
        while (r < s.size()) {
            if (s[r] == 'x') break;
            if (s[r] == 'o') {
                ok = true;
                break;
            }
            r++;
        }
        if (ok && (r - l) % 2 == 0) return true;
    }
    return false;
}

int main() {
    ll t;
    std::cin >> t;
    while (t--) std::cout << (solve() ? 'O' : 'X') << '\n';
    return 0;
}