#ifdef NACHIA
#define _GLIBCXX_DEBUG
#else
#define NDEBUG
#endif
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>
#include <array>
#include <cmath>
#include <atcoder/modint>
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<int(n); i++)
#define repr(i,n) for(int i=int(n)-1; i>=0; i--)
const i64 INF = 1001001001001001001;
const char* yn(bool x){ return x ? "Yes" : "No"; }
template<typename A> void chmin(A& l, const A& r){ if(r < l) l = r; }
template<typename A> void chmax(A& l, const A& r){ if(l < r) l = r; }
template<typename A> using nega_queue = std::priority_queue<A,std::vector<A>,std::greater<A>>;
using Modint = atcoder::static_modint<998244353>;
//#include "nachia/vec.hpp"
using namespace std;

void unit(){
    int N; cin >> N;
    string S; cin >> S;
    vector<string> A;
    A.push_back("");
    for(char c : S){
        if(c == '-') A.push_back("");
        else A.back().push_back(c);
    }
    int count_nonempty = 0;
    int count_K = 0;
    int count_P = 0;
    int count_X = 0;
    for(auto& s : A) if(!s.empty()){
        count_nonempty++;
        if(s.front() == 'K' && s.back() == 'K') count_K++;
        else if(s.front() == 'P' && s.back() == 'P') count_P++;
        else count_X++;
    }
    if(count_K >= count_P) cout << "K\n"; else cout << "P\n";
}

void testcase(){
    int T; cin >> T;
    rep(t,T) unit();
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    #ifdef NACHIA
    int T; cin >> T; for(int t=0; t<T; T!=++t?(cout<<'\n'),0:0)
    #endif
    testcase();
    return 0;
}