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#include <cstdio>
#include <vector>
#include <set>

using namespace std;

int main() {
  int n,m,d;
  scanf("%d%d%d",&n,&m,&d);
  vector<vector<int>> g(n);
  set<int> d_cities;
  for (int i = 0; i < m; ++i) {
    int a, b;
    scanf("%d%d", &a, &b);
    g[a-1].push_back(b-1);
    if (g[a-1].size() == d) {
      d_cities.insert(a-1);
    }
    g[b-1].push_back(a-1);
    if (g[b-1].size() == d) {
      d_cities.insert(b - 1);
    }
  }
  vector<int> neigh_count(n);
  int d_n = 0;
  for (int c : d_cities) {
    for(int n : g[c]) {
      if (++neigh_count[n] == d) {
	d_n++;
      }
    }
  }
  vector<int> decr_d;
  decr_d.reserve(d_cities.size() - d_n);
  for (int c : d_cities) {
    if (neigh_count[c] < d) {
      decr_d.push_back(c);
    }
  }
  while (!decr_d.empty()) {
    vector<int> new_decr;
    for (int c : decr_d) {
      d_cities.erase(c);
      for (int nc : g[c]) {
	if (--neigh_count[nc] == d-1) {
	  new_decr.push_back(nc);
	}
      }
    }
    decr_d.swap(new_decr);
  }

  set<int> visited;
  set<int> best_set;

  for (int c : d_cities) {
    if (visited.count(c)) {
      continue;
    }
    set<int> curr_set, fringe;
    fringe.insert(c);
    while (!fringe.empty()) {
      int cc = *fringe.begin();
      fringe.erase(fringe.begin());
      curr_set.insert(cc);
      for (int nc : g[cc]) {
	visited.insert(nc);
	if (curr_set.count(nc) == 0 && d_cities.count(nc)) {
	  fringe.insert(nc);
	}
      }
    }
    if (curr_set.size() > best_set.size()) {
      best_set = curr_set;
    }
  }
  
  if (best_set.empty()) {
    printf("NIE\n");
  } else {
    printf("%lu\n", best_set.size());
    for (int c : best_set) {
      printf("%d ", c+1);
    }
    printf("\n");
  }
}