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import java.util.*;

/**
 * Created by kamil on 29.09.15.
 */
public class mis {



    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int cities_no = scanner.nextInt();
        int routes_no = scanner.nextInt();
        int d = scanner.nextInt();

        Set<Integer>[] neighbors = new Set[cities_no];
        for(int i = 0;i<routes_no;i++){
            int from = scanner.nextInt()-1;
            int to = scanner.nextInt()-1;
            Set<Integer> n1 = neighbors[from];
            if(n1==null){
                n1 = new HashSet<>();
                neighbors[from]=n1;
            }
            n1.add(to);
            Set<Integer> n2 = neighbors[to];
            if(n2==null){
                n2 = new HashSet<>();
                neighbors[to] = n2;
            }
            n2.add(from);
        }

        Set<Integer> survived = new HashSet<>();
        Set<Integer> rejected = new HashSet<>();
        for(int i = 0 ; i<cities_no; i++){
            survived.add(i);
        }

        int[] deg = new int[cities_no];
        for(int i = 0 ; i <cities_no;i++){
            if(neighbors[i]!=null) deg[i] = neighbors[i].size();
        }

        while(true){

            for(Integer city:survived){
                if(deg[city]<d){
                    rejected.add(city);
                    Set<Integer> nbs = neighbors[city];
                    if(nbs!=null){
                        for(Integer nb:nbs){
                            deg[nb]--;
                        }
                    }
                }
            }

            survived.removeAll(rejected);




            if(rejected.isEmpty()){
                break;
            } else {
                rejected.clear();
            }
        }

        if(survived.size()<=1){
            System.out.println("NIE");
        } else {
            Set<Integer> biggest_cluster = null;
            while(!survived.isEmpty()){
                Set<Integer> cluster = new HashSet<>();
                Set<Integer> to_visit = new HashSet<>();
                to_visit.add(survived.iterator().next());
                while(!to_visit.isEmpty()){
                    Set<Integer> visited = new HashSet<>();
                    Set<Integer> to_add = new HashSet<>();
                    for(Integer visiting:to_visit){
                        visited.add(visiting);
                        for(Integer nb:neighbors[visiting]){
                            if(!cluster.contains(nb) && deg[nb]>=d){
                                to_add.add(nb);
                            }
                        }
                    }
                    to_visit.addAll(to_add);
                    cluster.addAll(visited);
                    to_visit.removeAll(visited);
                    survived.removeAll(visited);
                }

                if(biggest_cluster==null){
                    biggest_cluster = cluster;
                } else if(biggest_cluster.size()<cluster.size()){
                    biggest_cluster = cluster;
                }
                if(biggest_cluster.size()>=survived.size()){
                    break;
                }
            }

            survived = biggest_cluster;
            Integer[] output = new Integer[survived.size()];
            int j =0;
            for(Integer survivor:survived){
                output[j] = survivor+1;
                j++;
            }
            Arrays.sort(output);



            System.out.println(output.length);

            //System.exit(0);

            for(int i = 0;i<output.length-1;i++){
                System.out.print(output[i]);
                System.out.print(" ");
            }
            System.out.println(output[output.length - 1]);
        }


    }

}