#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
using ll = long long;
using ull = unsigned long long;

inline void solve() {
  int n;
  string s;
  cin >> n >> s;
  string ans = "-1";
  for (int i = n - 10; i >= 0; --i) {
    string t = s.substr(i, 10);
    bool match = true;
    rep(j, 10) {
      if (t[j] == '?' || t[j] == "helloworld"[j]) continue;
      match = false;
      break;
    }
    if (match) {
      string u = s;
      rep(j, 10) u[i + j] = "helloworld"[j];
      rep(j, n) if (u[j] == '?') u[j] = 'a';
      if (ans == "-1" || u < ans) ans = u;
    }
  }
  cout << ans << '\n';
}

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int t;
  cin >> t;
  while (t--) solve();
  return 0;
}