/*#pragma GCC target("arch=skylake-avx512")
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")*/
#include<bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
template<typename T>
using vec = vector<T>;
using ll = long long;
using ull = unsigned long long;
using vi = vec<int>;
using vs = vec<string>;
using si = set<int>;
using sll = set<ll>;
using vc = vec<char>;
using vvi = vec<vi>;
using vll = vec<ll>;
using vvll = vec<vll>;
using vsi = vec<si>;
using vsll = vec<sll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using mii = map<int, int>;
using mll = map<ll, ll>;
using msi = map<string, int>;
using vpii = vec<pii>;
using vpll = vec<pll>;
using spii = set<pii>;
using spll = set<pll>;
#define rep(i,j,n) for(ll i=j;i<n;i++)
#define rrep(i,j,n) for (ll i = n-1; i >=j; i--)
#define rp(i,n) rep(i,0,n)
#define rrp(i,n) rrep(i,0,n)
#define all(v) v.begin(), v.end()
#define pb push_back
#define ins insert
#define yes cout<<"Yes"<<endl;
#define no cout<<"No"<<endl; 
#define yn(jg) cout<<(jg? "Yes":"No")<<endl;
#define NL {cout<<endl;}
#define n0 {cout<<"-1"<<endl;}
#define fst first
#define snd second
#define lwb lower_bound
#define upb upper_bound
#define sz size()
#define fi first
#define se second
#define nxp next_permutation
ll mod0 = 998244353, lmax = 1e18, inf = 2e9;
double pi = 3.141592653589793238462643, E = 2.71828182846;
template<typename... T>
void in(T&... X) { (cin >> ... >> X); }/*
template<typename T>
void ain(vec<T>& Y) { rp(K, Y.size()) cin >> Y[K]; }
template<typename T>
void ain(set<T>& Y, auto n) {
	rp(i, n) {
		T YY; cin >> YY;
		Y.insert(YY);
	}
}
template<typename T>
void ain(multiset<T>& Y, auto n) {
	rp(i, n) {
		T YY; cin >> YY;
		Y.insert(YY);
	}
}*/
template<typename T>
void bin(vec<vec<T>>& Z) { rp(L, Z.size()) ain(Z[L]); }
template<typename T>
void aout(T& a) { for (auto I : a) cout << I << " "; cout << endl; }
template<typename T>
void aout(queue<T> a) {
	while (!a.empty()) { cout << a.front(); a.pop(); }
}
template<typename T>
void aout(stack<T> a) {
	while (!a.empty()) { cout << a.top(); a.pop(); }
}
#define bout(a) {for(auto J:a) aout(J);}
template<typename T>
bool chmin(T& M1, T M2) {
	if (M1 > M2) { M1 = M2; return 1; }
	else return 0;
}
template<typename T>
bool chmax(T& M1, T M2) {
	if (M1 < M2) { M1 = M2; return 1; }
	else return 0;
}
template<typename T>
auto vmax(T& a) {
	return *max_element(all(a));
}
template<typename T>
auto vmin(T& a) {
	return *min_element(all(a));
}
vector<pair<char, ll>>  rle(string rr) {
	vector<pair<char, ll>> ret;
	char lc;
	rep(i, 0, rr.size()) {
		if (i > 0 && rr[i] == lc) ret[ret.sz - 1].second++;
		else { ret.pb({ rr[i],1 }); }
		lc = rr[i];
	}
	return ret;
}
vector<pair<int, ll>>  rle(vi rr) {
	vector<pair<int, ll>> ret;
	int lc;
	rep(i, 0, rr.size()) {
		if (i > 0 && rr[i] == lc) ret[ret.sz - 1].second++;
		else { ret.pb({ rr[i],1 }); }
		lc = rr[i];
	}
	return ret;
}
vector<pair<ll, ll>>  rle(vll rr) {
	vector<pair<ll, ll>> ret;
	ll lc;
	rep(i, 0, rr.size()) {
		if (i > 0 && rr[i] == lc) ret[ret.sz - 1].second++;
		else { ret.pb({ rr[i],1 }); }
		lc = rr[i];
	}
	return ret;
}
template<typename T>
auto lwa(vector<T>& a, T b) {//aでbより小さい最大の値のイテレータ
	auto i = lwb(all(a), b);
	if (i == a.begin()) return a.end();
	else i--;
	return i;
}
template<typename T>
auto lwa(set<T>& a, T b) {//aでbより小さい最大の値のイテレータ
	auto i = a.lwb(b);
	if (i == a.begin()) return a.end();
	else i--;
	return i;
}
template<typename T>
auto lwa(multiset<T>& a, T b) {//aでbより小さい最大の値のイテレータ
	auto i = a.lwb(b);
	if (i == a.begin()) return a.end();
	else i--;
	return i;
}
template<typename T>
auto lwc(vector<T>& a, T b) {//aでb以下の最大の値のイテレータ
	auto i = lwb(all(a), b);
	if (i != a.end() && *i == b) return i;
	if (i == a.begin()) return a.end();
	else i--;
	return i;
}
template<typename T>
auto lwc(set<T>& a, T b) {//aでb以下の最大の値のイテレータ
	auto i = a.lwb(b);
	if (i != a.end() && *i == b) return i;
	if (i == a.begin()) return a.end();
	else i--;
	return i;
}
template<typename T>
auto lwc(multiset<T>& a, T b) {//aでb以下の最大の値のイテレータ
	auto i = a.lwb(b);
	if (i != a.end() && *i == b) return i;
	if (i == a.begin()) return a.end();
	else i--;
	return i;
}

template<typename T>
vec<T> rsw(vec<T>& a) {//累積和
	vec<T> b = a;
	rep(i, 1, b.size()) b[i] += b[i - 1];
	return b;
}
bool kai(string S) {//回文か判定
	bool ans = 1;
	rp(i, S.size()) if (S[i] != S[S.size() - 1 - i]) ans = 0;
	return ans;
}


sll yk(ll n) {//約数全列挙O(sqrt(N)),set<int>
	sll yaku;
	for (ll i = 1; i * i <= n; i++) if (n % i == 0) {
		yaku.insert(i);
		yaku.insert(n / i);
	}
	return yaku;
}
vi ssa(int n) {//n:必要な素数の最大値 素数全列挙
	vector<int> prime;
	vector<int>lpf(n + 1, 0);
	rep(i, 2, n + 1) {
		if (lpf[i] == 0) {
			lpf[i] = i;
			prime.push_back(i);
		}
		for (int k : prime) {
			if (k * i > n || k > lpf[i]) break;//k最小素因数よりk<=i
			lpf[k * i] = k;//kを最小素因数に持つ数k*iを拾う
		}
	}
	return prime;
}
vector<pll> sib(ll x) {//素因数分解
	if (x == 1) return vector<pll>(1, { 1,1 });
	vector<pll> ans;
	for (ll i = 2; i * i <= x; i++) {//rootx回iを回しxで割る
		ll kaisu = 0;
		while (x % i == 0) {
			x /= i; kaisu++;
		}
		if (kaisu > 0) ans.pb({ i,kaisu });
	}
	if (x != 1) ans.pb({ x,1 });
	return ans;
}
template<typename T>
vec<T> zat(vec<T> a) {//座標圧縮
	auto b = a;
	sort(all(b));
	b.erase(unique(all(b)), b.end());
	vec<T> c(a.size());
	rp(i, a.size()) {
		c[i] = lwb(all(b), a[i]) - b.begin();
	}
	return c;
}
template<typename T>
void cp(map < T, ll >& a, T b, ll c) {//countplus
	if (a.find(b) == a.end()) a[b] = c;
	else a[b] += c;
	if (a[b] == 0) a.erase(b);
}
template<typename T>
vec<T> inv(vec<T> a) {//0-indexed 逆関数
	vec<T> ans(a.sz);
	rp(i, a.sz) {
		ans[a[i]] = i;
	}
	return ans;
}
//lazy_segtree<S, op, e, F, mapping, composition, id> seg(n);
//S:中身型 op:左右合成 e:単位元(a･e=e･a=a)
//F:遅延型 mapping:遅延適用後の要素 composition:遅延合成( 関数f(g()) ) id:遅延初期値(何もさせない)
using S = pair<mint,int>;
using F = pair<mint,mint>;
S op(S a,S b) {
	return { a.fi + b.fi,a.se + b.se };
}

S e() {
	return { 0,0 };
}
S mapping(F x, S a) {//xをaに作用(x初期値に注意)
	return { a.fi * x.fi + x.se * a.se,a.se };
}
F composition(F f, F g) {//fの方が後(f初期値に注意)
	return {f.fi*g.fi,g.se*f.fi+f.se};
}
F id() { return {1,0}; }
//cout<<setprecision(15)<<fixed<<
//function<返り値の型(引数の型1, 引数の型2, ...)> 関数名 = [&](引数の型1 引数名1, 引数の型2, 引数名2, ...) 

int main() {
	int t;
	cin >> t;
	while (t--) {
		ll n; string s;
		cin >> n>>s;
		s.pb('-'); n++;
		bool r = 0,nn=0;
		int p=0, k = 0,t=0;
		rp(i, n) {
			if (s[i] != '-' && r==0) {
				r = 1;
				if (s[i] == 'P') nn = 0;
				else nn = 1;
			}
			if (s[i] == '-' && r == 1) {
				r = 0;
				if (s[i - 1] == 'P' && nn == 0) p++;
				else if (s[i - 1] == 'P') t++;
				else if (nn == 0) t++;
				else k++;
			}
		}
		if (p <= k) cout << "K";
		else cout << "P";
		cout << endl;
	}
}