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import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;
import java.util.Comparator;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;

public class mis {

	private static class City {
		final int id;

		Set<City> neighbours;

		boolean visited;

		public City(int id) {
			this.id = id;
			neighbours = new HashSet<>();
			visited = false;
		}

		@Override
		public int hashCode() {
			return id;
		}

		@Override
		public boolean equals(Object obj) {
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			City other = (City) obj;
			if (id != other.id)
				return false;
			return true;
		}

	}

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		makeResult();
		System.exit(0);

	}

	private static void makeResult() {
		BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
		StreamTokenizer st = new StreamTokenizer(bufferedReader);
		try {
			st.nextToken();
			int n = (int) st.nval;
			st.nextToken();
			int m = (int) st.nval;
			st.nextToken();
			int d = (int) st.nval;

			City[] cities = new City[n + 1];
			for (int i = 1; i <= n; i++) {
				cities[i] = new City(i);
			}
			int a, b = 0;
			for (int i = 1; i <= m; i++) {
				st.nextToken();
				a = (int) st.nval;
				st.nextToken();
				b = (int) st.nval;
				cities[a].neighbours.add(cities[b]);
				cities[b].neighbours.add(cities[a]);
			}
			bufferedReader.close();

			SortedSet<City> atLastD = new TreeSet<mis.City>(Comparator.comparing(c -> c.id));
			for (int i = 1; i <= n; i++) {
				if (cities[i].neighbours.size() < d)
					atLastD.add(cities[i]);
			}
			while (!atLastD.isEmpty()) {
				City city = atLastD.first();
				for (City c : city.neighbours) {
					c.neighbours.remove(city);
					if (c.neighbours.size() < d)
						atLastD.add(c);
				}
				city.neighbours = new HashSet<mis.City>();
				atLastD.remove(city);
			}

			int elements = 0;
			for (int i = 1; i <= n; i++) {
				if (cities[i].neighbours.size() >= d)
					elements++;
			}

			City[] world = new City[elements];

			elements = 0;
			for (int i = 1; i <= n; i++) {
				if (cities[i].neighbours.size() >= d)
					world[elements++] = cities[i];
			}

			List<City> result = new LinkedList<>();

			for (int i = 0; i < elements; i++) {
				if (!world[i].visited) {
					List<City> actualResult = new LinkedList<>();
					List<City> queue = new LinkedList<>();
					world[i].visited = true;
					queue.add(world[i]);
					actualResult.add(world[i]);

					while (!queue.isEmpty()) {
						City city = queue.remove(0);
						for (City c : city.neighbours) {
							if (!c.visited) {
								c.visited = true;
								queue.add(c);
								actualResult.add(c);
							}
						}
					}

					if (actualResult.size() > result.size())
						result = actualResult;

				}
			}

			if (result.size() < 2) {
				System.out.println("NIE");
				return;
			}

			System.out.println(result.size());
			result.sort(Comparator.comparing(c -> c.id));
			result.forEach(c -> System.out.print(c.id + " "));

		} catch (Exception e) {
			e.printStackTrace();
		}
	}

}