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

using namespace std;

vector<int> best_component(const vector<vector<int>> &G,
                           const vector<bool> &valid) {
  vector<int> visited(G.size(), 0);

  for (auto i = 1; i < G.size(); i++)
    if (!valid[i])
      visited[i] = -1;

  int i = 1, k = 1, best = 0, best_k = 0;
  while (i < G.size()) {
    if (visited[i]) {
      i++;
      continue;
    }

    int num = 0;
    queue<int> Q;

    Q.push(i);
    while (!Q.empty()) {
      int v = Q.front();
      Q.pop();
      visited[v] = k;
      num++;
      for (auto w : G[v])
        if (!visited[w])
          Q.push(w);
    }

    if (num > best) {
      best = num;
      best_k = k;
    }

    k++;
  }

  vector<int> out;
  if (best_k > 0) {
    out.reserve(best);
    for (auto i = 0; i < G.size(); i++)
      if (visited[i] == best_k)
        out.push_back(i);
  }

  return out;
}

int main() {
  ios_base::sync_with_stdio(false);
  int n, m, d;
  int w, v;

  cin >> n >> m >> d;

  vector<vector<int>> G(n + 1, vector<int>());
  vector<int> degs(n + 1, 0);
  vector<bool> valid(n + 1, false);
  queue<int> to_remove;

  for (auto i = 0; i < m; ++i) {
    cin >> w >> v;
    G[w].push_back(v);
    G[v].push_back(w);
    degs[w]++;
    degs[v]++;
    valid[w] = valid[v] = true;
  }

  for (auto i = 1; i <= n; ++i) {
    if (degs[i] < d)
      to_remove.push(i);
  }

  while (!to_remove.empty()) {
    v = to_remove.front();
    to_remove.pop();
    valid[v] = false;
    for (auto w : G[v]) {
      if (valid[w] && --degs[w] < d)
        to_remove.push(w);
    }
  }

  auto out = best_component(G, valid);
  if (out.empty())
    cout << "NIE" << endl;
  else {
    cout << out.size() << endl;
    for (auto x : out)
      cout << x << " ";
    cout << endl;
  }
  return 0;
}