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#include <stdio.h>
#include <set>
#include <queue>
#include <utility>

using namespace std;

class CompareDist
{
public:
    bool operator()(pair<int,int> n1,pair<int,int> n2) {
        return n1.second<n2.second;
    }
};

set<int> *graph = new set<int>[200001];
//priority_queue<int> myqueue;
priority_queue<pair<int,int>,vector<pair<int,int> >,CompareDist> myqueue;
set<int>::iterator it;
int colors[200001];
pair <int,int> foo;

int colorize(int v,int color) {
  queue<int> myqueue2;
  myqueue2.push(v);
  
  int result = 0;
  
  while (!myqueue2.empty())
  {
     v = myqueue2.front();
     myqueue2.pop();
     if (colors[v]!=0) continue;
     colors[v]=color;
     ++result;
     for (it=graph[v].begin(); it!=graph[v].end(); ++it) {
	 
	 myqueue2.push(*it);
       }
  }
  return result;
  
}

int main() {
  int n,m,d,a,b;
  int i,size;
  scanf("%d %d %d", &n, &m, &d);
  
  
  
  for(int i=0; i<m; ++i) {
    scanf("%d %d", &a, &b);
    graph[a].insert(b);
    graph[b].insert(a);
  }
  
  for(int i=1; i<=n; ++i) {
    if (graph[i].size()<d) {
      myqueue.push(make_pair(i,graph[i].size()));
    }
  }
  
  while (!myqueue.empty())
  {
     foo = myqueue.top();
     i = foo.first;
     myqueue.pop();
     if (graph[i].size()<d) {
       for (it=graph[i].begin(); it!=graph[i].end(); ++it) {
	 graph[*it].erase(i);
	 myqueue.push(make_pair(*it, graph[*it].size()));
       }
	graph[i].clear();
     }
  }
  
  //kolorowanie grafu
  for(int i=1; i<=n; ++i) {
    colors[i]=0;
  }
  
  int color=1,result;
  int best_result=0, best_color=0;
  for(int i=1; i<=n; ++i) {
    if (colors[i]==0) {
      result = colorize(i,color);
      if (result>=d && result>best_result) {
	best_result=result;
	best_color=color;
      }
	
      //printf("%d\n", result);
      color++;
    }
  }
  
  if (best_result==0)
    printf("NIE");
  else {
    printf("%d\n", best_result);
    for(int i=1; i<=n; ++i) {
      if (colors[i]==best_color)
	printf("%d ", i);
    }
  }
  
  return 0;
}