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#include <iostream>
#include <vector>
#include <stack>
#include <unordered_set>
#include <set>
#include <algorithm>

using namespace std;

void getConnectedComponents(const vector<vector<int>> &graph, const unordered_set<int> &goodCities, vector<vector<int>> &components) {
	vector<bool> visited(graph.size(), false);
	int currComponent = 0;
	for(int i=0; i<graph.size(); i++) {
		if((visited[i]) || (goodCities.count(i) == 0))
			continue;
		stack<int> toDo;
		toDo.push(i);
		visited[i] = true;
		components.push_back(vector<int>{});
		while(!toDo.empty()) {
			int curr = toDo.top();
			toDo.pop();
			components.back().push_back(curr);
			for(auto it = graph[curr].cbegin(); it != graph[curr].cend(); ++it) {
				if((visited[*it]) || (goodCities.count(*it) == 0))
					continue;
				toDo.push(*it);
				visited[*it] = true;
			}
		}
	}
}

struct city {
	int idx;
	int degree;
	city(int i, int d): idx(i), degree(d) {};
	bool operator<(const city &c) const noexcept {
		if(degree == c.degree)
			return idx < c.idx;
		return degree < c.degree;
	}
};


int main() {
	ios_base::sync_with_stdio(false);
	vector<vector<int>> graph;
	vector<vector<int>> connectedComponents;
	vector<int> degrees;
	set<city> cityQueue;
	unordered_set<int> goodCities;
	int N, M, d;
	cin >> N;
	cin >> M;
	cin >> d;
	graph.resize(N);
	int a, b;
	for(int i=0; i<M; i++) {
		cin >> a;
		cin >> b;
		graph[a-1].push_back(b-1);
		graph[b-1].push_back(a-1);
	}
	for(int i=0; i<graph.size(); i++) {
		degrees.push_back(graph[i].size());
		cityQueue.insert(city(i, graph[i].size()));
	}
	while((!cityQueue.empty()) && (cityQueue.begin()->degree < d)) {
		int currIdx = cityQueue.begin()->idx;
		cityQueue.erase(cityQueue.begin());
		degrees[currIdx] = 0;
		for(int i=0; i<graph[currIdx].size(); i++) {
			if(degrees[graph[currIdx][i]] == 0)
				continue;
			auto it = cityQueue.find(city(graph[currIdx][i], degrees[graph[currIdx][i]]));
			cityQueue.erase(it);
			degrees[graph[currIdx][i]]--;
			cityQueue.insert(city(graph[currIdx][i], degrees[graph[currIdx][i]]));
		}
	}	
	for(auto it = cityQueue.cbegin(); it != cityQueue.cend(); ++it) {	
		goodCities.insert(it->idx);
	}
	if(goodCities.empty()) {
		cout << "NIE" << endl;
		return 0;
	}
	getConnectedComponents(graph, goodCities, connectedComponents);
	int maxIdx, maxCount = 0;;
	for(int i=0; i<connectedComponents.size(); i++) {
		if(maxCount < connectedComponents[i].size()) {
			maxCount = connectedComponents[i].size();
			maxIdx = i;
		}
	}
	sort(connectedComponents[maxIdx].begin(), connectedComponents[maxIdx].end());
	cout << maxCount << endl;
	for(auto a : connectedComponents[maxIdx])
		cout << a+1 << " ";
	cout << endl;
	return 0;
}