#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <cmath>
#include <iomanip>
#include <stack>
#include <queue>
#include <numeric>
#include <map>
#include <unordered_map>
#include <set>
#include <fstream>
#include <chrono>
#include <random>
#include <bitset>
//#include <atcoder/all>
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) ((int)(x).size())
#define pb push_back
using ll = long long;
using namespace std;
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) {return a/gcd(a,b)*b;}

int ok(string S,int i){
  string s = "helloworld";
  for(int x=i;x<i+10;x++){
    if(S[x]=='?') continue;
    if(S[x]!=s[x-i]) return 0;
  }
  return 1;
}

string rpl(string S,int i){
  string s = "helloworld";
  rep(j,10){
    S[i+j] = s[j];
  }
  rep(i,sz(S)) if(S[i]=='?') S[i]='a';
  return S;
}

int main(){
  int T; cin >> T;
  while(T--){
    int N; cin >> N;
    string S; cin >> S;
    string ans = "";
    int flag = 0;
    rep(i,N-9){
      if(ok(S,i)){
        if(!flag){
          ans = rpl(S,i);
        }
        else{
          chmin(ans,rpl(S,i));
        }
        flag = 1;
      }
    }
    if(!flag) cout << -1 << endl;
    else cout << ans << endl;
  }
  return 0;
}