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import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class mis {

    static int n;
    static int m;
    static int d;

    static HashSet<Integer> connected[];
    static HashSet<Integer> selectedSet;
    static HashSet<Integer> removedSet;

    static void readInput() throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer fl = new StringTokenizer(br.readLine());
        n = Integer.parseInt(fl.nextToken());
        m = Integer.parseInt(fl.nextToken());
        d = Integer.parseInt(fl.nextToken());
        connected = new HashSet[n];
        for (int i = 0; i < n; i++) connected[i] = new HashSet<>();
        for (int i = 0; i < m; i++) {
            StringTokenizer nl = new StringTokenizer(br.readLine());
            int a = Integer.parseInt(nl.nextToken()) - 1;
            int b = Integer.parseInt(nl.nextToken()) - 1;
            connected[a].add(b);
            connected[b].add(a);
        }
    }

    static class SelectedAndRemoved {
        HashSet<Integer> selected;

        HashSet<Integer> removed;

        SelectedAndRemoved(HashSet<Integer> selected, HashSet<Integer> removed) {
            this.selected = selected;
            this.removed = removed;
        }
    }

    static SelectedAndRemoved sweep() {
        HashSet<Integer> newSelected = new HashSet<>();
        HashSet<Integer> newRemoved = new HashSet<>();
        for (Integer i : selectedSet) {
            if (connected[i].size() >= d) {
                newSelected.add(i);
            } else {
                newRemoved.add(i);
            }
        }
        return new SelectedAndRemoved(newSelected, newRemoved);
    }

    static void printOutput(Set<Integer> maximalSet) {
        if (maximalSet.isEmpty()) {
            System.out.println("NIE");
        } else {
            System.out.println(maximalSet.size());
            Integer[] maximalList = maximalSet.toArray(new Integer[maximalSet.size()]);
            Arrays.sort(maximalList);
            StringJoiner sj = new StringJoiner(" ");
            for (int i : maximalList) sj.add(Integer.toString(i+1));
            System.out.println(sj.toString());
        }
    }

    static Set<Integer> findConnected() {
        Iterator<Integer> it = selectedSet.iterator();
        if (it.hasNext()) {
            Set<Integer> conComp = new HashSet<>();
            Queue<Integer> que = new LinkedList<>();
            Integer v = it.next();
            conComp.add(v);
            que.add(v);
            while (!que.isEmpty()) {
                v = que.remove();
                for (Integer con : connected[v]) {
                    if (conComp.add(con)) {
                        que.add(con);
                    }
                }
            }
            return conComp;
        } else return Collections.emptySet();
    }

    public static void main(String[] args) throws IOException {
        readInput();
        selectedSet = new HashSet<>();
        removedSet = new HashSet<>();
        for (int i = 0; i < n; i++) selectedSet.add(i);
        for (SelectedAndRemoved sar = sweep(); !sar.removed.isEmpty(); sar = sweep()) {
            selectedSet = sar.selected;
            for (int i : selectedSet) {
                connected[i].removeAll(sar.removed);
            }
        }

        Set<Integer> maximalSet = Collections.emptySet();
        while (selectedSet.size() > maximalSet.size()) {
            Set<Integer> conComp = findConnected();
            if (conComp.size() > maximalSet.size()) maximalSet = conComp;
            selectedSet.removeAll(conComp);
        }
        printOutput(maximalSet);
    }
}