#include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < (n); i++)
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = 1001001001;
const ll LINF = 1001002003004005006ll;
//const int mod = 1000000007;
//const int mod = 998244353;

void solve(){
  int n;
  string s;
  cin >> n >> s;
  string t = "helloworld";
  if (s.find("helloworld") != string::npos) {
    rep(i, 0, s.size()) {
      if (s[i] == '?') cout << 'a';
      else cout << s[i];
    }
    cout << endl;
    return;
  }
  string ans;
  for (int i = n-10; i >= 0; i--) {
    bool flag = true;
    string c = s;
    rep(j, 0, t.size()) {
      if (s[i+j] == t[j] || s[i+j] == '?') c[i+j] = t[j];
      else flag = false;
    }
    if (flag) {
      rep(j, 0, c.size()) if (c[j] == '?') c[j] = 'a';
      if (ans.size() == 0) ans = c;
      else ans = min(ans, c);
    }
  }
  if (ans.size() == 0) cout << -1 << endl;
  else cout << ans << endl;
  return;
}

int main()
{
  int t;
  cin >> t;
  while(t--) solve();
  return 0;
}