#include <bits/stdc++.h>
using namespace std;

vector<pair<char,int>> RLEa(string &s){
    vector<pair<char,int>> ret;
    char back = s.at(0); int streak = 1;
    for(int i=1; i<s.size(); i++){
        if(back == s.at(i)) streak++;
        else{
            ret.push_back({back,streak});
            back = s.at(i); streak = 1;
        }
    }
    ret.push_back({back,streak});
    return ret;
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    
    int T; cin >> T;
    while(T--){
        int N; cin >> N;
        string s; cin >> s; s += '-';       
        auto S = RLEa(s);
        int K = 0,P = 0;
        for(auto[c,len] : S){
            if(c == 'P') P++;
            if(c == 'K') K++;
        }

        if(K >= P) cout << "K" << endl;
        else cout << "P" << endl;
    }
}