#include<iostream>
#include<map>
#include<string>
#include<vector>
#include<utility>

using namespace std;

map<string, int> corri;

typedef int point;

struct edge
{
  point dest;
  edge(){};
  edge(const point & dest): dest(dest){};
};


typedef vector<edge> edges;
typedef map<point, edges> graph;

graph thegraph, connected_graph;


pair<string, string> split(const string & s)
{
  string r1, r2;
  int pos = s.find('-');
  
  return make_pair(s.substr(0, pos), 
		   s.substr(pos + 1));
}

int strees_to_num(const string& c)
{
  if(corri.count(c) == 0)
    {
      // add
      corri.insert(c, corri.size());
    }
  return corri[c];
}

void add_edge(string src, string dest)
{
  int s = street_to_num(src);
  int d = street_to_num(dest);

  thegraph[src].push_back(edge(dest));
}

void solve()
{
  // copy
  connected_graph = thegraph;
  for(graph::iterator it = thegraph.begin();
      it != thegraph.end();
      it++)
    {
    }
}

int main(void)
{
  int n;
  cin >> n;
  if(n == 0)
    return;
  for( int i = 0; i < n; i++)
    {
      corri.clear();
      thegreph.clear();
      connected_graph.clear();

      string crossing;
      cin >> crossing;

      pair<string, string> p = split(crossing);
      
      add_edge(p.first, p.second);
    }
  solve();
}

map<set<point > > classify()
{
  

}