#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <map>
#include <vector>
#include <string>
using namespace std;

class Node {
  public: 
    string name;
    vector <class Edge *> adj;
    int visited;
};

class Edge {
  public:
    string name;
    Node *n1;
    Node *n2;
    Edge *reverse;
    double original;
    double residual;
    double flow;
};

class Graph {
  public:
     Graph();
     ~Graph();
     void Print();
     Node *Get_Node(string &s);
     Edge *Get_Edge(Node *n1, Node *n2);
     Node *Source;
     Node *Sink;
     vector <Node *> Nodes; 
     vector <Edge *> Edges; 
     map <string, Node *> N_Map;
     map <string, Edge *> E_Map;
};

void Graph::Print()
{
  Node *n;
  int i;

  printf("Source: %s\n", Source->name.c_str());
  printf("Sink:   %s\n", Sink->name.c_str());
  printf("Nodes: ");

  for (i = 0; i < Nodes.size(); i++) {
    n = Nodes[i];
    printf(" %s", n->name.c_str());
  }
  printf("\n");
}

Graph::Graph()
{
  string s, f, t;
  double cap;
  Node *n1, *n2;

  Source = NULL;
  Sink = NULL;

  while (cin >> s) {
    if (s == "SOURCE") {
      cin >> s;
      if (Source != NULL) { fprintf(stderr, "Can't specify two sources\n"); exit(1); }
      Source = Get_Node(s);
    } else if (s == "SINK") {
      cin >> s;
      if (Sink != NULL) { fprintf(stderr, "Can't specify two sinks\n"); exit(1); }
      Sink = Get_Node(s);
    } else if (s == "EDGE") {
      cin >> f >> t >> cap;

      n1 = Get_Node(f);
      n2 = Get_Node(t);
    }
  }

  if (Source == NULL) { fprintf(stderr, "No Source.\n"); exit(1); }
  if (Sink == NULL) { fprintf(stderr, "No Sink.\n"); exit(1); }
}

Graph::~Graph()
{
  int i;

  for (i = 0; i < Nodes.size(); i++) delete(Nodes[i]);
  for (i = 0; i < Edges.size(); i++) delete(Edges[i]);
}

Node *Graph::Get_Node(string &s)
{
  map <string, Node *>::iterator nit;
  Node *n;

  nit = N_Map.find(s);
  if (nit != N_Map.end()) return nit->second;

  n = new Node;
  n->name = s;
  Nodes.push_back(n);
  N_Map.insert(make_pair(s, n));
  return n;
}

main()
{
  Graph *g;

  g = new Graph();
  g->Print();
}