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#include <iostream>
#include <vector>
#include <queue>

using namespace std;

struct City
{
  City()
    : inS(true)
    , degree(0)
    , inRes(0)
  {
  }

  bool inS;
  int degree;
  int inRes;

  vector<City*> neighbours;
};

int main()
{
  ios_base::sync_with_stdio(false);

  int N, M, D;

  cin >> N >> M >> D;

  vector<City> cities(N);

  for (int i = 0; i < M; i++)
  {
    int A, B;
    cin >> A >> B;

    cities[A-1].neighbours.push_back(&cities[B-1]);
    cities[B-1].neighbours.push_back(&cities[A-1]);
    cities[A-1].degree++;
    cities[B-1].degree++;
  }

  queue<City*> outOfS;

  for (int i = 0; i < N; i++)
  {
    if (cities[i].degree < D)
    {
      cities[i].inS = false;
      outOfS.push(&cities[i]);
    }
  }

  while (!outOfS.empty())
  {
    City *city = outOfS.front();
    outOfS.pop();

    for (auto &n: city->neighbours)
    {
      if (n->inS)
      {
        n->degree--;
        if (n->degree < D)
        {
          n->inS = false;
          outOfS.push(n);
        }
      }
    }
  }

  int whichOne = 1;
  int maxcnt = 0;
  int whichMax = 0;

  for (auto &c: cities)
  {
    if (c.inS)
    {
      queue<City*> bfs;
      bfs.push(&c);
      c.inS = false;
      c.inRes = whichOne;

      int maxlocal = 1;
      // go and mark inS false and result to whichOne
      while (!bfs.empty())
      {
        City *city = bfs.front();
        bfs.pop();

        for (auto &n: city->neighbours)
        {
          if (n->inS)
          {
            maxlocal++;
            n->inS = false;
            n->inRes = whichOne;
            bfs.push(n);
          }
        }
      }

      if (maxlocal>maxcnt) 
      {
        maxcnt = maxlocal;
        whichMax = whichOne;
      }
      whichOne++;
    }
  }

  if (0 == maxcnt) cout << "NIE" << endl;
  else
  {
    cout << maxcnt << endl;
    for (int i = 0; i < N; i++)
    {
      if (cities[i].inRes == whichMax) cout << i+1 << " ";
    }
    cout << endl;
  }

  return 0;
}