#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<ll,ll>;
#define fix(x) fixed << setprecision(x)
#define asc(x) x, vector<x>, greater<x>
#define rep(i, n) for(ll i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()
template<class T>bool chmin(T&a, const T&b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool chmax(T&a, const T&b){if(a<b){a=b;return 1;}return 0;}
constexpr ll INFLL = (1LL << 62), MOD = 998244353;
constexpr int INF = (1 << 30);

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int t;
    cin >> t;
    rep(houren,t){
        int n;
        string s, ans, t = "helloworld";
        ans = "{";
        cin >> n >> s;
        rep(i,n-9){
            string x = s;
            bool ok = true;
            rep(j,10){
                if(s[i+j]=='?') x[i+j] = t[j];
                if(x[i+j]!=t[j]) ok = false;
            }
            if(ok){
                rep(i,n) if(x[i]=='?') x[i] = 'a';
                chmin(ans,x);
            }
        }
        cout << (ans.size()==n?ans: "-1") << '\n';
    }
    return 0;
}