#include <bits/stdc++.h> using namespace std; using ll = long long; int main() { int T; cin >> T; int N; string S; const string B = "helloworld"; bool pos; for(int test = 0; test < T; test++) { cin >> N >> S; pos = false; // helloworld が既にある for(int i = 0; i < N - 9; i++) { for(int j = 0; j < 10; j++) { if(S[i + j] != B[j]) break; if(j == 9) pos = true; } } if(pos) { for(int j = 0; j < N; j++) if(S[j] == '?') S[j] = 'a'; cout << S << endl; continue; } vector<string> v; for(int i = N - 10; i >= 0; i--) { string s = S; pos = false; for(int j = 0; j < 10; j++) { if(s[i + j] != B[j] && s[i + j] != '?') break; if(j == 9) pos = true; } if(pos) { for(int j = 0; j < 10; j++) s[i + j] = B[j]; for(int j = 0; j < N; j++) if(s[j] == '?') s[j] = 'a'; v.push_back(s); } } if((int)v.size() == 0) cout << -1 << endl; else { sort(v.begin(), v.end()); cout << v[0] << endl; } } return 0; }