#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rrep(i, n) for (int i = (int)(n - 1); i >= 0; i--)
#define all(x) (x).begin(), (x).end()
#define sz(x) int(x.size())
using namespace std;
using ll = long long;
const int INF = 1e9;
const ll LINF = 1e18;
template <class T>
void get_unique(vector<T>& x) {
    x.erase(unique(x.begin(), x.end()), x.end());
}
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;
}
template <class T>
vector<T> make_vec(size_t a) {
    return vector<T>(a);
}
template <class T, class... Ts>
auto make_vec(size_t a, Ts... ts) {
    return vector<decltype(make_vec<T>(ts...))>(a, make_vec<T>(ts...));
}
template <typename T>
istream& operator>>(istream& is, vector<T>& v) {
    for (int i = 0; i < int(v.size()); i++) {
        is >> v[i];
    }
    return is;
}
template <typename T>
ostream& operator<<(ostream& os, const vector<T>& v) {
    for (int i = 0; i < int(v.size()); i++) {
        os << v[i];
        if (i < sz(v) - 1) os << ' ';
    }
    return os;
}
string h = "helloworld";
bool match(const string& s) {
    if (sz(s) != sz(h)) return false;
    rep(i, sz(h)) {
        if (s[i] == '?') continue;
        if (s[i] != h[i]) return false;
    }
    return true;
}
void solve() {
    int n;
    string s;
    cin >> n >> s;
    string ans(n + 1, 'z');
    rep(i, n) {
        if (!match(s.substr(i, sz(h)))) continue;
        string t = s;
        rep(j, sz(h)) t[i + j] = h[j];
        rep(j, n) if (t[j] == '?') t[j] = 'a';
        chmin(ans, t);
    }
    if (sz(ans) > n) ans = "-1";
    cout << ans << '\n';
}
int main() {
    int tt;
    cin >> tt;
    while (tt--) solve();
}