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#include <cstdio>
#include <vector>
#include <queue>
#include <algorithm>

using namespace std;

vector< vector<int> > preV, V;
vector< vector<int> > group_members;
vector<int> edge_count;
vector<bool> visi;

int n, m, d;


queue<int> fixQ;

void fix() {

	for(int i = 0; i < n; i++) {
		if(edge_count[i] < d) {
			// printf("%d has less that %d edges\n", i, d);
			fixQ.push(i);
		}
	}

	while(!fixQ.empty()) {

		int front = fixQ.front();
		// printf("front = %d\n", front);
		fixQ.pop();
		edge_count[front] = 0;

		for(int i = 0; i < preV[front].size(); i++) {
			// printf("\tchecking %d\n", preV[front][i]);
			if(edge_count[ preV[front][i] ] > 0) {
				// printf("\t\t%d stole one edge from %d\n", front, preV[front][i]);
				edge_count[ preV[front][i] ]--;
			}
			if(edge_count[ preV[front][i] ] == d-1) {
				// printf("\t\tcomes out that %d has less that %d edges\n", i, d);
				fixQ.push(preV[front][i]);
			}
		}

		V[front].clear();

	}

}

void count_group(int x, int repr) {
	// printf("count_group(%d, %d)\n", x, repr);

	group_members[repr].push_back(x);
	visi[x] = true;

	for(int i = 0; i < V[x].size(); i++)
		if(!visi[ V[x][i] ])
			count_group(V[x][i], repr);

}

int main() {
	
	scanf("%d%d%d", &n, &m, &d);

	V.resize(n);
	preV.resize(n);
	edge_count.resize(n);
	group_members.resize(n);
	visi.resize(n);

	int end1, end2;
	for(int i = 0; i < m; i++) {
		scanf("%d%d", &end1, &end2);
		end1--; end2--;
		preV[end1].push_back(end2);
		preV[end2].push_back(end1);  
	}

	for(int i = 0; i < n; i++)
		edge_count[i] = preV[i].size();

	// printf("edge_count: ");
	// for(int i = 0; i < n; i++)
	// 	printf("%d ", i);
	// 	// if(edge_count[i] >= d)
	// printf("\n");

			
	fix();
	// printf("end fix\n");

	for(int i = 0; i < n; i++) {
		if(edge_count[i] >= d) {
			// is candidate
			for(int j = 0; j < preV[i].size(); j++) {
				if(edge_count[ preV[i][j] ] >= d) {
					V[i].push_back(preV[i][j]);
				}
			}
		}
	}

	// printf("edges\n");
	// for(int i = 0; i < n; i++) {
	// 	if(edge_count[i] >= d) {
	// 		printf("%d:", i);
	// 		for(int j = 0; j < V[i].size(); j++) {
	// 			printf(" %d", V[i][j]);
	// 		}
	// 		printf("\n");
	// 	}
	// }
	// printf("\n");

	// printf("edge_count: ");
	// for(int i = 0; i < n; i++)
	// 	if(edge_count[i] >= d)
	// 		printf("%d ", edge_count[i]);
	// printf("\n");

	// return 0;

	// graph V now consists only of vertices that have >= d
	// edges to other vertices matching this requirement

	for(int i = 0; i < n; i++)
		if(edge_count[i] >= d && !visi[i])
			count_group(i, i);

	// printf("gm_count: ");
	// for(int i = 0; i < n; i++)
	// 	if(group_members[i].size() > 0)
	// 		printf("%d ", group_members[i].size());


	int max_value = 0, max_group = 0;
	for(int i = 0; i < n; i++) {
		if(group_members[i].size() > max_value) {
			max_value = group_members[i].size();
			max_group = i;
		}
	}

	if(max_value < d) {
		printf("NIE");
		return 0;
	}

	sort(group_members[max_group].begin(), group_members[max_group].end());

	printf("%d\n", group_members[max_group].size());
	for(int i = 0; i < group_members[max_group].size(); i++)
		printf("%d ", group_members[max_group][i]+1);
	// printf("\n");

	return 0;
}