#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using pll=pair<ll,ll>;
using tll=tuple<ll,ll,ll>;
using ld=long double;
const ll INF=(1ll<<60);
#define rep(i,n) for (ll i=0;i<(ll)(n);i++)
#define all(v) v.begin(),v.end()
template<class T> inline bool chmin(T &a,T b){
    if(a>b){
        a=b;
        return true;
    }
    return false;
}
template<class T> inline bool chmax(T &a,T b){
    if(a<b){
        a=b;
        return true;
    }
    return false;
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll t;
    cin >> t;
    while(t--){
        ll n;
        string s;
        cin >> n >> s;
        s.push_back('X');
        ll p=0,k=0;
        rep(i,n){
            if(s[i]!=s[i+1]){
                if(s[i]=='P') p++;
                if(s[i]=='K') k++;
            }
        }
        if(p<=k) cout << "K\n";
        else cout << "P\n";
    }
}