func_code_string: #include <bits/stdc++.h>   using namespace std;   void connected(vector<vector<bool> > chu, vector<bool>& v, int s) {     v[s] = 1;     for (int i = 0; i < chu.size(); i++) {       if (chu[s][i] && !v[i]) {         connected(chu, v, i);       }     }   }   int main() {     int n, m;     while (cin >> n >> m) {       if (n != m) {         cout <<  NO  << endl;         break;       }       vector<vector<bool> > chu(n, vector<bool>(n, 0));       for (int i = 0; i < m; i++) {         int e1, e2;         cin >> e1 >> e2;         chu[e1 - 1][e2 - 1] = 1;         chu[e2 - 1][e1 - 1] = 1;       }       vector<bool> visisted(n, 0);       connected(chu, visisted, 0);       bool allseen = true;       for (int i = 0; i < visisted.size(); i++) {         if (!visisted[i]) allseen = false;       }       if (allseen) {         cout <<  FHTAGN!  << endl;       } else {         cout <<  NO  << endl;       }     }     return 0;   }   