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#include <iostream>
#include <set>
#include <map>
#include <stack>

int s[200000];
int size[200000];


int main(){

  int n, m, d;

  std::cin >> n >> m >> d;

  std::set<int> c[n];

  while(m--){
    int a, b;

    std::cin >> a >> b;

    c[a-1].insert(b-1);
    c[b-1].insert(a-1);
  }

  std::stack<int> w;

  for(int i=0; i<n; ++i){
    if(c[i].size() < d){
      s[i] = -1;
      w.push(i);
    }
  }

  while(! w.empty()){
    int x = w.top(); w.pop();
    for(std::set<int>::iterator it = c[x].begin(); it != c[x].end(); ++it){
      c[*it].erase(x);
      if(c[*it].size() < d && s[*it] != -1){
        s[*it] = -1;
        w.push(*it);
      }
    }
  }
 
  
  int tag = 1;  int max = -1;
  int max_tag = 1;
  for(int i=0; i<n; ++i){
    if(s[i]!=0) continue;

    w.push(i);
    s[i] = tag;
    while(!w.empty()){
      int x = w.top(); w.pop();
      
      ++size[tag];
      for(std::set<int>::iterator it = c[x].begin(); it != c[x].end(); ++it){
        if(s[*it]==0){
          w.push(*it);
          s[*it] = tag;}

      }
    }
    if(size[tag] > max){
      max = size[tag];
      max_tag = tag;
    }
    ++tag;
  }

  if(max == -1){
    printf("NIE\n");
    return 0;
  }


  printf("%d\n", max); 
  for(int i=0; i<n; ++i){
    if(s[i] == max_tag) printf("%d ", i+1);
  }
  printf("\n");
  return 0;
}