#include <iostream>
#include <string>
#include <set>
using namespace std;
int main(){
    int i,n; cin >> n;
    string s; cin >> s;
    int cnt = 0;
    set<int> st;
    for(i=0;i<n;i++){
        if(s[i]=='H'){
            cout << -1 << endl;
            return 0;
        }
        if(s[i]=='Q') cnt++;
    }
    for(i=1;i*i<=n;i++) st.insert(i*i);
    if(!st.count(cnt)){
        cout << -1 << endl;
        return 0;
    }
    if(cnt==1){
        cout << s << endl;
        return 0;
    }
    int j = -1;
    for(i=1;i*i<=n;i++){
        if(i*i==cnt) j = i;
    }
    if(n%j!=0){
        cout << -1 << endl;
        return 0;
    }
    string t,u;
    for(i=0;i<n/j;i++) t.push_back(s[i]);
    while(u.size()<n) u += t;
    if(u!=s) cout << -1 << endl;
    else cout << t << endl;
}