#include <algorithm>
#include <iostream>
#include <numeric>
#include <string>
#include <tuple>
#include <type_traits>
#include <utility>
#include <vector>
#include <limits>

#define rep(i, a, b) for (int i = int(a); i < int(b); i++)
using namespace std;
using ll = long long int;  // NOLINT
using P = pair<ll, ll>;

// clang-format off
#ifdef _DEBUG_
#define dump(...) do{ cerr << __LINE__ << ":\t" << #__VA_ARGS__ << " = "; debug_print(__VA_ARGS__); } while(false)
template<typename T, typename... Ts> void debug_print(const T &t, const Ts &...ts) { cerr << t; ((cerr << ", " << ts), ...); cerr << endl; }
template<typename T> struct IsVector : std::false_type {};
template<typename T> struct IsVector<std::vector<T>> : std::true_type {};
template<typename T> ostream &dump_v(const vector<T> &vec, ostream &os = cerr, int indent = 0) {
    if constexpr (IsVector<T>::value) {
        os << string(indent, ' ') << "[\n";
        for (auto it = vec.begin(); it != vec.end(); ++it) dump_v(*it, os, indent + 2) << ",\n";
        os << string(indent, ' ') << "]";
    } else {
        os << string(indent, ' ') << "[";
        for (auto it = vec.begin(); it != vec.end(); ++it) os << (it == vec.begin() ? "" : ", ") << *it;
        os << "]";
    }
    return indent == 0 ? os << endl : os;
}
#else
#define dump(...) do{ } while(false)
#define dump_v(...) do{ } while(false)
#endif
template<typename T> vector<T> make_v(size_t a, T b) { return vector<T>(a, b); }
template<typename... Ts> auto make_v(size_t a, Ts... ts) { return vector<decltype(make_v(ts...))>(a, make_v(ts...)); }
template<typename T> bool chmin(T &a, const T& b) { if (a > b) {a = b; return true; } return false; }
template<typename T> bool chmax(T &a, const T& b) { if (a < b) {a = b; return true; } return false; }
template<typename T, typename... Ts> void print(const T& t, const Ts&... ts) { cout << t; ((cout << ' ' << ts), ...); cout << '\n'; }
constexpr static struct PositiveInfinity { template<typename T> constexpr operator T() const { return numeric_limits<T>::max() / 2; } constexpr auto operator-() const; } inf;  // NOLINT
constexpr static struct NegativeInfinity { template<typename T> constexpr operator T() const { return numeric_limits<T>::lowest() / 2; } constexpr auto operator-() const; } NegativeInfinityVal;
constexpr auto PositiveInfinity::operator-() const { return NegativeInfinityVal; }
constexpr auto NegativeInfinity::operator-() const { return inf; }
// clang-format on

#include <type_traits>
template<typename T>
auto runlength(const T &v) {
    using E = remove_reference_t<decltype(declval<T>()[0])>;
    vector<pair<E, int>> res;
    for (auto &&e : v) {
        if (res.empty() || res.back().first != e) {
            res.emplace_back(e, 1);
        } else {
            res.back().second++;
        }
    }
    return res;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int t;
    cin >> t;
    while (t--) {
        int n;
        cin >> n;
        string s;
        cin >> s;
        auto v = runlength(s);
        int k = 0, p = 0;
        for (auto [c, cnt] : v) {
            if (c == 'K') {
                k++;
            } else if (c == 'P') {
                p++;
            }
        }
        print(k >= p ? "K" : "P");
    }

    return 0;
}