#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

void solve(){
    ll N;
    string S, T, U="helloworld";
    cin >> N >> S;
    vector<string> v;

    for (int i=0; i<=N-10; i++){
        bool f=1;
        T = S;
        for (int j=0; j<10; j++){
            if (S[i+j] != '?' && S[i+j] != U[j]){
                f=0;
                break;
            }
            if (S[i+j] == '?') T[i+j] = U[j];
        }
        for (int j=0; j<N; j++) if (T[j] == '?') T[j] = 'a';
        if (f) v.push_back(T);
    }
    if (v.size() == 0){
        cout << -1 << endl;
        return;
    }
    sort(v.begin(), v.end());
    cout << v[0] << endl;
}

int main(){

    int T;
    cin >> T;
    while(T){
        T--;
        solve();
    }

    return 0;
}