#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll MAX_N = 2e5;

void solve(){
    ll n; cin >> n;
    string s; cin >> s;

    string t="helloworld";
    for(ll i=(ll)s.size()-1; i>=9; i--){
        bool flag = true;
        rep(j, 10){
            if(!(s[i-9+j]==t[j] || s[i-9+j]=='?')){
                flag = false;
            }
        }

        if(flag){
            rep(j, 10){
                s[i-9+j]=t[j];
            }

            rep(i, (ll)s.size()) if(s[i]=='?') s[i]='a';

            cout << s << "\n";
            return;
        }
    }

    cout << -1 << "\n";
    return;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    
    ll t; cin >> t;
    rep(i, t) solve();
}