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#include <iostream>
#include <unordered_set>
#include <vector>
#include <stack>

using namespace std;

int n, m, d;

int maxSize = 1;
int indexMaxSize = 0;

int current = 0;

const int MAX = 200000;

vector<unordered_set<int>> A;
vector<int> degree;
vector<int> visited;

stack<int> S;

void removeEdges(int v)
{
  unordered_set<int>::iterator it;
  int u;
  bool changed = true;
  int currentSize = 1;

  current++;

  S.push(v);
  visited[v] = current;

  while(!S.empty() && changed)
  {
    v = S.top();
    changed = false;
    if(degree[v] < d)
    {
      S.pop();
      currentSize--;
      changed = true;

      while(!A[v].empty())
      {
        u = *A[v].begin();
        A[v].erase(u);
        A[u].erase(v);
        degree[u]--;
        if(!visited[u])
        {
          S.push(u);
          visited[u] = current;
          currentSize++;
        }
      }
      degree[v] = 0;
    }
    else
    {
      for(it = A[v].begin(); it != A[v].end(); ++it)
      {
        if(!visited[*it])
        {
          S.push(*it);
          visited[*it] = current;
          currentSize++;
          changed = true;
        }
      }
    }
  }
  if(currentSize > maxSize)
  {
    maxSize = currentSize;
    indexMaxSize = current;
  }
}

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

  int i, u, v;

  cin >> n >> m >> d;

  A = vector<unordered_set<int>>(n);
  visited = vector<int>(n, 0);
  degree = vector<int>(n, 0);

  for(i = 0; i < m; i++)
  {
    cin >> u >> v;
    u--;
    v--;
    A[u].insert(v);
    A[v].insert(u);
    degree[u]++;
    degree[v]++;
  }

  for(i = 0; i < n; i++)
  {
    if(!visited[i])
    {
      removeEdges(i);
    }
  }

  if(maxSize < 2)
  {
    cout << "NIE\n";
    return 0;
  }

  cout << maxSize << "\n";
  for(i = 0; i < n; i++)
  {
    if(visited[i] == indexMaxSize && degree[i] > 0)
    {
      cout << i+1 << " ";
    }
  }
  cout << "\n";

  return 0;
}