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//============================================================================
// Name        : .cpp
// Author      : Grzegorz Gajoch
// Description : 
//============================================================================

#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <ctype.h>
#include <algorithm>
#include <string>
#include <string.h>
#include <cstring>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <list>

using namespace std;

#define FOR(i,a,b) for(int i = a; i <= b; ++i)
#define FORD(i,a,b) for(int i = a; i >= b; --i)
#define REP(x, n) for(int x=0; x < (n); ++x)
#define VAR(v,i) __typeof(i) v=(i)
#define FOREACH(i,c) for(VAR(i,(c).begin());i!=(c).end();++i)
#define SIZE(n) (int)n.size()
#define ALL(c) c.begin(),c.end()
#define PB(n) push_back(n)
typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<vector<int> > VVI;
typedef vector<bool> VB;
#define MP make_pair
#define ST first
#define ND second
const int INF = 1000000001;

#undef DEBUG
#ifdef DEBUG 
#define debug printf
#else
#define debug 
#endif

int V, E, D;
vector< set < int > > Nodes;
vector< int > Connections;
set< pair<int, int> > ConnSet; // (connections, node)
vector< int > vis;
vector<int> result;

void print() {
	FOR(i, 1, V) {
		debug("Node %d: %d | ", i, Connections[i]);
		FOREACH(it, Nodes[i]) {
			debug("%d ", *it);
		}
		debug("\n");
	}
	debug("ConnSet:\n");
	FOREACH(it, ConnSet) {
		debug("%d -> %d\n", it->second, it->first);
	}
}


void resize() {
	Nodes.resize(V+1);
	Connections.resize(V+1, 0);
	vis.resize(V+1);
}
void clear_vis() {
	FOREACH(it, vis) {
		*it = 0;
	}
}
void read() {
	scanf("%d %d %d", &V, &E, &D);
	resize();
	REP(i, E) {
		int a, b;
		scanf("%d %d", &a, &b);
		if( a == b ) {
			printf("EQUAL INPUTS!!!!!!\n");
			exit(-1);
		}
		Nodes[a].insert(b);
		Nodes[b].insert(a);
		Connections[a]++;
		Connections[b]++;
	}
	FOR(i, 1, V) {
		ConnSet.insert(MP(Connections[i], i));
	}
}

void delete_node(int nr) {
	debug("Deleting %d\n", nr);
	FOREACH(it, Nodes[nr]) {
		int dest = *it;
		debug("Conn (%d, %d)\n", nr, dest);
		Nodes[dest].erase(nr);
		ConnSet.erase(MP(Connections[dest], dest));
		Connections[dest]--;
		ConnSet.insert(MP(Connections[dest], dest));
	}
	ConnSet.erase(MP(Connections[nr], nr));
	Connections[nr] = 0;
	Nodes[nr].clear();
}

pair<int, int> take_min() {
	pair<int, int> P = *ConnSet.begin();
	return P;
}

void dfs(int node, int value) {
	//debug("dfs: %d -> %d\n", node, value);
	vis[node] = value;
	FOREACH(it, Nodes[node]) {
		if( vis[*it] == 0 ) {
			dfs(*it, value);
		}
	}
}

void start_dfs(int start, int value) {
	std::stack<int> Dfs;
	Dfs.push(start);
	do {
		int top = Dfs.top();
		Dfs.pop();
		vis[top] = value;
		FOREACH(it, Nodes[top]) {
			if( vis[*it] == 0 ) {
				Dfs.push(*it);
			}
		}
	} while (!Dfs.empty());
}
int do_dfs() {
	clear_vis();

	int v = 1;
	FOR(i, 1, V) {
		if( vis[i] == 0 && Connections[i] > 0 ) {
			debug("DFS start node %d -> %d\n", i, v);
			dfs(i, v);
			//start_dfs(i, v);
			v++;
		}
	}
	
	return v;
}


int main(int argc, char **argv) {
	read();
	//print();
	pair<int, int> p = take_min();
	while( p.first < D && !ConnSet.empty() ) {
		debug("smaller: %d -> %d\n", p.second, p.first);

		delete_node(p.second);
#ifdef DEBUG
		//print();
#endif
		p = take_min();
	}
	if( ConnSet.empty() ) {
		printf("NIE\n");
	} else {
		int s = do_dfs();
		debug("subsets: %d\n", s);

		vector<int> subset_sizes;
		subset_sizes.resize(s+1, 0);
		FOR(i, 1, V) {
			subset_sizes[vis[i]]++;
			debug("%d in subset %d\n", i, vis[i]);
		}

		//pair<int, int> subset_max = MP(0, 0); //size, number
		int max_size = 0, max_nr = 0;
		FOR(i, 1, s) {
			debug("subset %d -> %d nodes\n", i, subset_sizes[i]);
			if( subset_sizes[i] > max_size ) {
				max_nr = i;
				max_size = subset_sizes[i];
			}
		}

		debug("max subset: %d -> %d\n", max_nr, max_size);
		
		FOR(i, 1, V) {
			if( Connections[i] >= D && vis[i] == max_nr ) {
				result.push_back(i);
			}
		}
		sort(ALL(result));
		printf("%d\n", result.size());
		FOREACH(it, result) {
			printf("%d ", *it);
		}
		printf("\n");
	}
}