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import java.io.*;
import java.util.*;

/**
 * Created by gmatuszewski on 30.09.2015.
 */
public class mis {

	public static void main(String[] args) throws IOException {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));

		mis(br, bw);

		bw.flush();
		bw.close();
		System.exit(0);
	}

	static boolean[] visited;
	static Map<Integer, List<Integer>> connections;

	public static void mis(BufferedReader br, BufferedWriter bw) throws IOException {
		StringTokenizer st;
		st = new StringTokenizer(br.readLine());

		int n = Integer.parseInt(st.nextToken());
		int m = Integer.parseInt(st.nextToken());
		int d = Integer.parseInt(st.nextToken());

		visited = new boolean[n];

		connections = new HashMap<>();
		for (int i = 0; i < n; i++) {
			connections.put(i, new ArrayList<>());
		}

		while (m-- > 0) {
			st = new StringTokenizer(br.readLine());

			int c1 = Integer.parseInt(st.nextToken()) - 1;
			int c2 = Integer.parseInt(st.nextToken()) - 1;

			connections.get(c1).add(c2);
			connections.get(c2).add(c1);
		}

		// remove small cities;
		TreeSet<Integer> testRemoval = new TreeSet<>(connections.keySet());
		while(!testRemoval.isEmpty()) {
			int city = testRemoval.pollFirst();
			if (connections.get(city).size() < d) {
				visited[city] = true;

				for(Integer c : connections.get(city)){
					connections.get(c).remove(Integer.valueOf(city));
					testRemoval.add(c);
				}
				connections.get(city).clear();
			}
		}


		List<Integer> cities = Collections.emptyList();
		for (int i = 0; i < n; i++) {
			if (visited[i])
				continue;

			List<Integer> set = compute(i);
			if (set.size() > cities.size())
				cities = set;
		}

		Collections.sort(cities);
		if (cities.size() == 0)
			bw.write("NIE");
		else {
			bw.write(Integer.toString(cities.size()));
			bw.newLine();

			for (Integer city : cities) {
				bw.write(Integer.toString(city + 1));
				bw.write(" ");
			}

			bw.newLine();
		}
	}

	private static List<Integer> compute(int startCity) {
		List<Integer> cities = new ArrayList<>();
		TreeSet<Integer> toVisit = new TreeSet<>();
		toVisit.add(startCity);

		while (!toVisit.isEmpty()) {
			int city = toVisit.pollFirst();

			if (visited[city])
				continue;

			cities.add(city);
			visited[city] = true;

			toVisit.addAll(connections.get(city));
		}

		return cities;
	}
}