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/*
 *  Copyright (C) 2015  Paweł Widera
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details:
 *  http://www.gnu.org/licenses/gpl.html
 */
#include <iostream>
#include <vector>
#include <deque>
#include <unordered_set>
#include <algorithm>
using namespace std;


void remove_node(vector<unordered_set<int>>& graph, int node, unordered_set<int>& nodes) {
	for (auto i : graph[node]) {
		graph[i].erase(node);
	}
	graph[node].clear();
	nodes.erase(node);
}


int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	int n, m, d;
	cin >> n >> m >> d;

	// read graph
	int source, target;
	vector<unordered_set<int>> graph(n);
	for (int i = 0; i < m; ++i) {
		cin >> source >> target;
		graph[source - 1].insert(target - 1);
		graph[target - 1].insert(source - 1);
	}

	// copy nodes (to track nodes left after removals)
	unordered_set<int> nodes;
	unordered_set<int> check;
	for (int i = 0; i < n; ++i) {
		nodes.insert(i);
		check.insert(i);
	}

	// remove nodes with degree < d
	while (!check.empty()) {
		int node = *begin(check);
		if ((int) graph[node].size() < d) {
			// make sure all connected nodes are checked later
			for (auto altered: graph[node]) {
				check.insert(altered);
			}
			remove_node(graph, node, nodes);
		}
		check.erase(node);
	}

	// graph too small
	if ((int) nodes.size() < d + 1) {
		cout << "NIE" << endl;
		return 0;
	}

	unordered_set<int> cities;
	deque<int> queue;
	vector<int> best;

	while (nodes.size() > best.size()) {

		// find a node with maximum degree
		int max_degree = *begin(nodes);
		for (auto node: nodes) {
			if (graph[max_degree].size() < graph[node].size()) {
				max_degree = node;
			}
		}

		// breadth-first search
		queue.push_back(max_degree);
		cities.insert(max_degree);
		while (!queue.empty()) {
			int node = queue[0];
			queue.pop_front();

			for (auto connected : graph[node]) {
				if (cities.count(connected) == 0) {
					cities.insert(connected);
					queue.push_back(connected);
				}
			}
		}

		// remove cities from the graph
		for (auto node: cities) {
			remove_node(graph, node, nodes);
		}

		// remember the largest set of cities
		if (best.size() < cities.size()) {
			best.clear();
			best.reserve(cities.size());
			for (auto node: cities) {
				best.push_back(node);
			}
		}
		cities.clear();
	}

	cout << best.size() << endl;
	sort(begin(best), end(best));
	for (auto i: best) {
		cout << i + 1 << " ";
	}
	cout << endl;

	return 0;
}