#include<bits/stdc++.h>
using namespace std;
using ll = long long int;
using ld = long double;
#define pow(n,m) powl(n,m);
#define sqrt(n) sqrtl(n);
const ll MAX = 5000000000000000000;
const ll MOD = 1000000007;
//998244353;
void randinit(){srand((unsigned)time(NULL));}
int main(){
    ll N;
    string S;
    cin >> N >> S;
    for(ll i = 0;i < N;i++){
        if(S[i] != 'Q'){
            cout << -1 << endl;
            return 0;
        }
    }
    for(ll i = 0;i <= N;i++){
        if(i * i == N){
            for(ll j = 0;j < i;j++){
                cout << "Q";
            }
            cout << endl;
            return 0;
        }
    }
    cout << -1 << endl;
}