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import java.util.Arrays;
import java.util.HashSet;
import java.util.Scanner;
import java.util.TreeSet;

public class mis {

	public static void main(String[] args) {
	    final int INFINITY = 999;
		Scanner sc = new Scanner(System.in);
	    int n=sc.nextInt();
	    int m=sc.nextInt();
	    int d=sc.nextInt();
	    int[][] ab = new int[m][2];
	    int[] degree = new int [n+1];
	    
	    System.err.println("d=" + d);
	    
	    TreeSet<Integer> nodesWithDegreeHigherOrEqualToD = new TreeSet<Integer>();
	    
	    for (int i=0; i<m; i++) {
	    	ab[i][0] = sc.nextInt();
	    	ab[i][1] = sc.nextInt();
	    	degree[ab[i][0]]++;
	    	degree[ab[i][1]]++;
	    }
	    
	    for (int i=0; i<m; i++) {
	    	System.err.println(ab[i][0] + " <-> " + ab[i][1]);
	    }
	    
	    for (int i=1; i<=n; i++) {
	    	System.err.println("degree["+i+"]="+degree[i]);
	    	if (degree[i] >= d) 
	    		nodesWithDegreeHigherOrEqualToD.add(i);
	    }
	    
	    System.err.println(nodesWithDegreeHigherOrEqualToD.toString());
	    
	    for (int i=0; i<m; i++) {
	    	if (nodesWithDegreeHigherOrEqualToD.contains(ab[i][0]) && !(nodesWithDegreeHigherOrEqualToD.contains(ab[i][1])))
	    		degree[ab[i][0]]--;
	    	
	    	if (!nodesWithDegreeHigherOrEqualToD.contains(ab[i][0]) && (nodesWithDegreeHigherOrEqualToD.contains(ab[i][1])))
	    		degree[ab[i][1]]--;
	    }
	    
	    boolean conditionOneDirectRoads = true;
	    boolean conditionTwoConnected = false;
	    
	    for (int i=1; i<=n; i++) {
	    	if (nodesWithDegreeHigherOrEqualToD.contains(i)) {
	    		System.err.println("innerDegree["+i+"]="+degree[i]);
	    		if (degree[i] < d)
	    			conditionOneDirectRoads = false;
	    	}
	    }
	    
	    System.err.println("conditionOneDirectRoads="+conditionOneDirectRoads);

	    if (conditionOneDirectRoads) {
	    int numberofvertices = n;
	    mis mis = new mis();
	    FloydWarshall fw = mis.new FloydWarshall(numberofvertices);
	    
//	    for (int i=0; i<m; i++) {
//	    	if (nodesWithDegreeHigherOrEqualToD.contains(ab[i][0]) && (nodesWithDegreeHigherOrEqualToD.contains(ab[i][1])))
//	    		fw.addEdge(ab[i][0], ab[i][1], 1);	
//	    }
	    int adjacency_matrix[][];
	    adjacency_matrix = new int[numberofvertices + 1][numberofvertices + 1];
	    
	    HashSet<String> edges = new HashSet<String>();
	    for (int i=0; i<m; i++) {
//    	if (nodesWithDegreeHigherOrEqualToD.contains(ab[i][0]) && (nodesWithDegreeHigherOrEqualToD.contains(ab[i][1])))
    		edges.add(ab[i][0] + "-" + ab[i][1]);	
	    }
	    
	    for (int source = 1; source <= numberofvertices; source++)
        {
            for (int destination = 1; destination <= numberofvertices; destination++)
            {
                if (edges.contains(source + "-" + destination)){
                	adjacency_matrix[source][destination] = 1;
                	adjacency_matrix[destination][source] = 1;
                }
                if (source == destination)
                {
                    adjacency_matrix[source][destination] = 0;
                    continue;
                }
                if (adjacency_matrix[source][destination] == 0)
                {
                    adjacency_matrix[source][destination] = INFINITY;
                }
            }
        }
	    
	    int[][] distances = fw.floydwarshall(adjacency_matrix);
	    conditionTwoConnected = true;
	    for (int i=1; i<=n; i++) {
	    	for (int j=1; j<i; j++) {
	    		if (nodesWithDegreeHigherOrEqualToD.contains(i) && nodesWithDegreeHigherOrEqualToD.contains(j)){
	    			System.err.print(distances[i][j] + ", ");
	    			if (distances[i][j] == INFINITY)
	    				conditionTwoConnected = false;
	    		}
	    	}
	    	System.err.println();
	    }
	    System.err.println("conditionTwoConnected="+conditionTwoConnected);
	    }
	    
	    if (conditionOneDirectRoads && conditionTwoConnected) {
	    	System.out.println(nodesWithDegreeHigherOrEqualToD.size());
	    	for(int i : nodesWithDegreeHigherOrEqualToD) {
	    		System.out.print(i + " ");
	    	}
	    } else {
	    	System.out.println("NIE");
	    }
	}
	
	public class FloydWarshall
	{
	    private int distancematrix[][];
	    private int numberofvertices;
	    public static final int INFINITY = 999;
	 
	    public FloydWarshall(int numberofvertices)
	    {
	        distancematrix = new int[numberofvertices + 1][numberofvertices + 1];
	        this.numberofvertices = numberofvertices;
	    }
	 
	    public int[][] floydwarshall(int adjacencymatrix[][])
	    {
	        for (int source = 1; source <= numberofvertices; source++)
	        {
	            for (int destination = 1; destination <= numberofvertices; destination++)
	            {
	                distancematrix[source][destination] = adjacencymatrix[source][destination];
	            }
	        }
	 
	        for (int intermediate = 1; intermediate <= numberofvertices; intermediate++)
	        {
	            for (int source = 1; source <= numberofvertices; source++)
	            {
	                for (int destination = 1; destination <= numberofvertices; destination++)
	                {
	                    if (distancematrix[source][intermediate] + distancematrix[intermediate][destination]
	                         < distancematrix[source][destination])
	                        distancematrix[source][destination] = distancematrix[source][intermediate] 
	                            + distancematrix[intermediate][destination];
	                }
	            }
	        }
	 
	        for (int source = 1; source <= numberofvertices; source++)
	            System.err.print("\t" + source);
	 
	        System.err.println();
	        for (int source = 1; source <= numberofvertices; source++)
	        {
	            System.err.print(source + "\t");
	            for (int destination = 1; destination <= numberofvertices; destination++)
	            {
	                System.err.print(distancematrix[source][destination] + "\t");
	            }
	            System.err.println();
	        }
	        
	        return distancematrix;
	    }
	}
}