104C - Cthulhu - CodeForces Solution

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define MAXN 105

int n, m, x, y, t1;
vector <int> v[MAXN];
bool visi[MAXN];

void dfs(int z){
  visi[z] = 1, t1++;
  for (int i = 0; i < v[z].size(); i++){
    if (!visi[v[z][i]]) dfs(v[z][i]);
  }
}

int main(){
  cin >> n >> m;
  for (int i = 0; i < m; i++){
    cin >> x >> y;
    v[x].pb(y), v[y].pb(x);
  }
  dfs(1);
  if (t1 != n or n != m) cout << "NO\n";
  else cout << "FHTAGN!\n";

  return 0;
}