#include <bits/stdc++.h>
using namespace std;
//#include <atcoder/all>
//using namespace atcoder;
//using mint = modint998244353;

//多倍長整数//
//#include <boost/multiprecision/cpp_int.hpp>
//namespace mp = boost::multiprecision;
//using bint = mp::cpp_int;

const int INF = 1e9;
const int MOD = 998244353;
const long long LINF = 4e18;

using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using vs = vector<string>;
using vc = vector<char>;
using vb = vector<bool>;
using vvi = vector<vector<int>>;
using vvvi = vector<vector<vector<int>>>;
using vvvvi = vector<vector<vector<vector<int>>>>;
using vvl = vector<vector<long long>>;
using vvvl = vector<vector<vector<long long>>>;
using vvvvl = vector<vector<vector<vector<long long>>>>;
using vvc = vector<vector<char>>;
using vvb = vector<vector<bool>>;
using vvvb = vector<vector<vector<bool>>>;
using vvvvb = vector<vector<vector<vector<bool>>>>;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define dump(x)  cout << #x << " = " << (x) << endl;
#define Yes(n) cout << ((n) ? "Yes" : "No"  ) << endl
#define ALL(obj) (obj).begin(),(obj).end()



vector<pair<char,int>> RLE(string s){
	vector<pair<char,int>> ans;
	if(s.size() == 0) return ans;
	int cnt = 1;
	for(int i = 1;i < s.size();i++){
		if(s[i] == s[i - 1]){
			cnt++;
			continue;
		}else{
			ans.push_back(make_pair(s[i - 1],cnt));
			cnt = 1;
		}
	}
	ans.push_back(make_pair(s[s.size() - 1],cnt));
	return ans;
}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	int t;
	cin >> t;
	for(;t--;){
		int n;
		cin >> n;
		string s;
		cin >> s;
		auto a = RLE(s);
		int kcnt = 0,pcnt = 0;
		for(auto i : a){
			if(i.first == 'P') pcnt++;
			else if(i.first == 'K') kcnt++;
		}
		if(pcnt <= kcnt) cout << "K\n";
		else cout << "P\n";
	}
	return 0;
}