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#include <cstdio>
#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <set>
using namespace std;

int n, m, d, a, b;

vector<vector<int> > G;
vector<int> degree;
vector<int> parent;

int find(int v) {
	if( parent[v]<0 ) return v;
	else return parent[v] = find(parent[v]);
}

void join(int u, int v) {
	u = find(u);
	v = find(v);
	if( u==v ) return;
	
	if( parent[u] < parent[v] ) {
		parent[u] += parent[v];
		parent[v] = u;
	} else {
		parent[v] += parent[u];
		parent[u] = v;
	}	
}



struct cmp{
	bool operator() (int i, int j) {
		if( degree[i]==degree[j] )
			return i<j;
		else
			return degree[i]<degree[j];
	}	
};

set<int,cmp> S;
set<int,cmp>::iterator it;


int main() {
	ios_base::sync_with_stdio(false);
	
	cin >> n >> m >> d;
	
	G.resize(n+1);
	degree.resize(n+1,0);
	for( int i=0 ; i<m ; i++ ) {
		cin >> a >> b;
		G[a].push_back(b);
		G[b].push_back(a);
		degree[a]++;
		degree[b]++;
	}
	
	for( int u=1 ; u<=n ; u++ )
		S.insert(u);
	
	while( !S.empty() ) {
		it = S.begin();
		if( degree[*it] < d ) {
			int u = *it;
			S.erase(it);
			degree[u] = -1;
			for( int i=0 ; i<G[u].size() ; i++ ) {
				if( degree[ G[u][i] ] < 0 )
					continue;
				S.erase( G[u][i] );
				degree[ G[u][i] ]--;
				S.insert( G[u][i] );
			}
		}
		else
			break;
	}
	
	if( S.empty() ) {
		cout << "NIE" << endl;
		return 0;
	}
	
	parent.resize(n+1,-1);
	
	for( int u=1 ; u<=n ; u++ ) {
		if( degree[u]>=d ) {
			for( int i=0 ; i<G[u].size() ; i++ ) {
				if( degree[ G[u][i] ]>=d )
					join( u, G[u][i] );
			}
		}
	}
	
	int biggest = 0;
	parent[biggest] = 0;
	for( int u=1 ; u<=n ; u++ )
		if( degree[u]>=d && parent[u]<parent[biggest] )
			biggest = u;
	
	cout << (-parent[biggest]) << endl;
	for( int u=1 ; u<=n ; u++ )
		if( find(u)==biggest )
			cout << u << " ";
	cout << endl;	
		
	return 0;
}