#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define rng(i,c,n) for(int i=c;i<n;i++)
#define fi first
#define se second
#define pb push_back
#define all(a) a.begin(), a.end()
#define sz(a) ((int) a.size())
#define vec(...) vector<__VA_ARGS__>
#define _49vEjP0 ios::sync_with_stdio(0),cin.tie(0);
typedef long long ll;
typedef vector<int> vi;
typedef pair<int,int> pii;
void print(){cout<<'\n';}
template<class h,class...t>
void print(const h&v,const t&...u){cout<<v<<' ',print(u...);}

void slv(){
	int n;
	cin>>n;
	string s;
	cin>>s;
	int p=0,k=0;
	rep(i,n){
		string wrd="";
		while(i<n and s[i]=='K' or s[i]=='P'){
			wrd+=s[i];
			i+=1;
		}
		if(sz(wrd) and wrd[0]==wrd.back()){
			if(wrd[0]=='P'){
				p+=1;
			}else{
				k+=1;
			}
		}
	}
	if(k>=p) cout<<"K\n";
	else cout<<"P\n";
}

signed main(){
_49vEjP0;
	int __t;
	cin>>__t;
	rep(cs,__t){
		slv();
	}	
}