const string t = "helloworld";

bool contain(string& s, ll x) {
  ll n = s.size();
  rep(i, 9) {
    if (s[i + x] != t[i]) {
      return false;
    }
  }
  return true;
}

bool imply(string& s, ll x) {
  ll n = s.size();
  rep(i, 9) {
    if (s[i + x] != t[i] && s[i + x] != '?') {
      return false;
    }
  }
  rep(i, 9) {
    if (s[i + x] == '?') {
      s[i + x] = t[i];
    }
  }
  return true;
}

void fill(string& s) {
  for (auto&& x : s) {
    if (x == '?') {
      x = 'a';
    }
  }
}

void solve() {
  ll @N;
  string @S;

  rep(i, (N - 9)) {
    if (contain(S, i)) {
      fill(S);
      wt(S);
      return;
    }
  }

  rrep(i, (N - 9)) {
    if (imply(S, i)) {
      fill(S);
      wt(S);
      return;
    }
  }

  wt(-1);
}

{
  REP(rd_int()) { solve(); }
}