// #include <bits/stdc++.h> using namespace std; using ll = long long; #define rep(i, n) for (int i=0; i<(int)(n); ++(i)) #define rep3(i, m, n) for (int i=(m); (i)<(int)(n); ++(i)) #define repr(i, n) for (int i=(int)(n)-1; (i)>=0; --(i)) #define rep3r(i, m, n) for (int i=(int)(n)-1; (i)>=(int)(m); --(i)) #define all(x) (x).begin(), (x).end() const string tar = "helloworld"; int main() { int t0; cin >> t0; rep(i0, t0) { int n; string s; cin >> n >> s; bool exist = false; int tlen = tar.length(); for (int i=0; i+tlen-1<n; ++i) if (s.substr(i, tlen) == tar) { exist = true; break; } if (exist) { rep(i, n) if (s[i] == '?') s[i] = 'a'; cout << s << endl; } else { vector<string> slst; for (int i=0; i+tlen-1<n; ++i) { bool ok = true; rep(j, tlen) if (s[i+j]!='?' && s[i+j]!=tar[j]) { ok = false; break; } if (ok) { auto ts = s; rep(j, tlen) ts[i+j] = tar[j]; rep(j, n) if (ts[j] == '?') ts[j] = 'a'; slst.push_back(ts); } } if (!slst.empty()) { sort(all(slst)); cout << slst[0] << endl; } else cout << -1 << endl; } } return 0; }