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import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;



class Graph {
	
	class Vertex implements Comparable<Vertex>{
		public int idx, label, degree, component;
		boolean active;
		
		public Vertex(int idx, int label) {
			this.idx = idx;
			this.label = label;
			this.degree = 0;
			this.component = -1;
			this.active = true;
		}
		
		public int deg() {
			return degree;
		}
		
		public boolean isActive() { 
			return this.active; 
		}
		
		public void deactivate() {
			//System.out.println("Removing "+label);
			this.active = false;
		}

		@Override
		public int compareTo(Vertex other) {
			int d = this.deg();
			int od = other.deg();
			
			if(d < od) {
				return -1;
			} else if (d > od) {
				return 1;
			} else {
				return 0;
			}
		}
		
		
	}
	
	int n,m;
	
	ArrayList<List<Integer>> edges;
	Vertex[] vertices;
	
	int color = 0;
	Map<Integer, List<Vertex>> components;
	
	
	public Graph(int n, int m) {
		this.n = n;
		this.m = m;
		
		vertices = new Vertex[n];
		components = new HashMap<Integer, List<Vertex>>();
		
		for(int i = 0; i < n; i++) {
			addVertex(new Vertex(i, i+1));
		}
		
		this.edges = new ArrayList<List<Integer>>();
		for(int i = 0; i < n; i++) {
			edges.add(new ArrayList<Integer>());
		}
	}
	
	public void addVertex(Vertex v) {
		this.vertices[v.idx] = v;
	}
	
	public void addEdge(int fromIdx, int toIdx) {
		edges.get(fromIdx).add(toIdx);
		vertices[fromIdx].degree++;
	}
	
	public void removeSmallVertices(int degLimit) {
		List<Vertex> verts = new ArrayList<Vertex>();
		for(Vertex v: vertices) {
			verts.add(v);
		}
		
		Collections.sort(verts);
		
		for(Vertex v: verts) {
			if (v.deg() < degLimit) {
				// remove v
				v.deactivate();
				
				for(int uIdx: edges.get(v.idx)) {
					vertices[uIdx].degree--;
				}
			}
		}
		//rebuildEdges();
	}
	
	private void addToComponent(int componentId, Vertex v) {
		if(!components.containsKey(componentId)) {
			components.put(componentId, new ArrayList<Vertex>());
		}
		
		components.get(componentId).add(v);
	}
	
	private void dfsVisit(Vertex u) {
		List<Integer> adj = edges.get(u.idx);
		u.component = color;
		addToComponent(color, u);
		
		
		
		for(int uIdx: adj){
			Vertex v = vertices[uIdx];
			if (v.component < 0 && v.isActive()) {
				dfsVisit(v);
			}
		}
	}
	
	public void markComponents() {
		
		for(Vertex v: vertices) {
			if (v.isActive()) {
				dfsVisit(v);
				color++;
			}
		}
	}
	
	public List<Integer> getBiggestComponent() {
		List<Integer> results = new ArrayList<Integer>();
		int mx = 0;
		int mxIdx = -1;
		for(Map.Entry<Integer, List<Vertex>> e: components.entrySet()) {
			int c = e.getKey();
			List<Vertex> verts = e.getValue();
			
			if (verts.size() > mx) {
				mx = verts.size();
				mxIdx = c;
			}
		}
		
		if(mx > 0){
			List<Vertex> cV = components.get(mxIdx);
			for(Vertex v : cV) {
				results.add(v.label);
			}
		}
		
		return results;
	}
}

public class mis {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int d = sc.nextInt();
		
		Graph G = new Graph(n,m);
		
		for (int i = 0; i < m; i++) {
			int a = sc.nextInt();
			int b = sc.nextInt();
			G.addEdge(a-1, b-1);
			G.addEdge(b-1, a-1);
		}
		
		G.removeSmallVertices(d);
		G.markComponents();
		
		List<Integer> r = G.getBiggestComponent();
		Collections.sort(r);
		if (r.size() > 0) {
			System.out.println(r.size());
			for(int i : r){
				System.out.print(i + " ");
			}
			
			System.out.println();
		} else {
			System.out.println("NIE");
		}
		
		sc.close();
	}

}