#include <iostream>
using namespace std;

void dfs (int curr, vector<vector<int>> graph, vector<int> visited, unordered_map<int, string> hash_id_to_name){
  //Print email or nickname of one person (To print only nickname, the hash could has an addional information
  //in the value, that can be a boolean that says if it is one or other.
  cout << hash_id_to_name[curr] << '\n';
  for (int i = 0; i < graph[curr].size(); i++){
    int adj = graph[curr][i];
    if (!visited[adj]){
      visited[adj] = true;
      dfs(adj, graph, visited, hash_id_to_name);
    }
  }
}

//receives a vector such that arr[i] = NickName, email1, email2, email3 ... emailN
int getGroups (vector< vector<strings> > arr_of_names) {
  vector< vector<int> > graph ;
  //given an email or a nickname as key, return a unic id integer representing that email/nickname
  unordered_map<string, int> hash_name_to_id;
  //opposite to the hash above
  unordered_map<int, string> hash_id_to_name;
  int next_id = 0;

  for (auto list_of_emails : arr_of_names){
    hash_name_to_id.insert(pair<string,int>(list_of_emails[0], next_id));
    hash_id_to_name.insert(pair<int,string>(next_id, list_of_emails[0]));
    graph.push_back(vector<int>());
    int idx_nickname = next_id ++;

    for (int i = 1; i < list_emails.size(); i++){
      string email = list_emails[i] ;
      int idx_email;

      //verify if this email has appeard
      auto it = hash_name_to_id.find(email);
      if (it == hash_name_to_id.end()){
        hash_name_to_id.insert(pair<string,int>(email, next_id));
        hash_id_to_name.insert(pair<int,string>(next_id, email));
        graph.push_back(vector<int>());
        idx_email = next_idx ++;
      }else
        idx_email = it->second;

      //put the new edges in the graph
      graph[idx_email].push_back(idx_nickname);
      graph[idx_nickname].push_back(idx_email);
    }
  }

  vector<bool> visited(next_id, 0);
  int cnt_people = 0;
  for (int i = 0; i < next_id; i++){
    //it is not visited
    if (!visited[i]){
      //Print vertex of one group
      dfs (i);
      cnt_people ++;
    }
  }
}

// To execute C++, please define "int main()"
int main() {


  return 0;
}

/*

First approach:

map<string, int>
(email, unic_id)

map<int, string>
(unic_id, email)

*/
/*
Input:

Site1:
Ana-dias: ana.dias@yahuu.com, ana-d@yahuu.com
ONinja: rui@coldmail.com, oNinja@tmail.com

Site2:
Rui42: rui.r@yahuu.com, rui@coldmail.com
Bbia: bia@coldmail.com, bb@coldmail.com

Site3:
Rui.Dias40: rui.r@yahuu.com
PedroA: pedro@yahuu.com, pedrinho@coldmail.com
Gil.P: gil.p@tmail.com

Site4:
Ana97: ana.dias@yahuu.com
Rui.Silva: rui.silve@coldmail.com
Ninja.7: oNinja@tmail.com


ana.dias@yahuu.com <-> Ana-dias, Ana97
ana.d@tmail.com <-> Ana-dias

rui.r@yahuu.com <-> Rui42, rui@coldmail.com, Rui.Dias40, ONinja, oNinja@tmail.com
oNinja@tmail.com <-> ONinja, Ninja.7


*/