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#include <iostream>
#include <set>
#include <vector>
#include <queue>

using namespace std;

#define DEBUG false
#define log if (DEBUG) cerr
typedef long long ll;
typedef unsigned long long ull;


struct City
{
    int id;
    int group;
    set<int> neighbours;
};

int n, m;
unsigned d;
vector<City> cities;


void readData()
{
    int i;

    cin >> n >> m >> d;
    cities.resize(n + 1);
    for (i = 0; i <= n; i++)
    {
        cities[i].id = i;
        cities[i].group = 0;
    }

    for (i = 0; i < m ; i++)
    {
        int a, b;
        cin >> a >> b;
        cities[a].neighbours.insert(b);
        cities[b].neighbours.insert(a);
    }
}


void stripNet()
{
    set<int> candidates;
    set<int> newCandidates;

    for (const City& city : cities)
    {
        if (city.neighbours.size() < d)
        {
            candidates.insert(city.id);
        }
    }

    while (!candidates.empty())
    {
        newCandidates.clear();
        for (int sourceId : candidates)
        {
            for (int destId : cities[sourceId].neighbours)
            {
                City& destCity = cities[destId];
                destCity.neighbours.erase(sourceId);
                if (destCity.neighbours.size() < d)
                {
                    newCandidates.insert(destId);
                }
            }
            cities[sourceId].neighbours.clear();
        }
        candidates = newCandidates;
    }

    if (DEBUG)
    {
        for (const City& city : cities)
        {
            if (!city.neighbours.empty())
            {
                log << city.id << ", ";
            }
        }
        log << endl;
    }
}


void groupAndCount()
{
    int currentGroup = 0;
    vector<set<int>> groupedIds;

    for (City& startCity : cities)
    {
        if (startCity.neighbours.size() < d || startCity.group != 0)
        {
            continue;
        }
        currentGroup ++;
        queue<int> toVisit;
        set<int> ids;

        startCity.group = currentGroup;
        toVisit.push(startCity.id);
        ids.insert(startCity.id);

        while (!toVisit.empty())
        {
            int visitCityId = toVisit.front();
            toVisit.pop();
            for (int cityId : cities[visitCityId].neighbours)
            {
                City& city = cities[cityId];
                if (city.group == 0)
                {
                    city.group = currentGroup;
                    toVisit.push(cityId);
                    ids.insert(city.id);
                }
            }
        }

        groupedIds.push_back(ids);
    }

    unsigned maxCount = 0;
    int maxIdx;
    for (size_t i = 0; i < groupedIds.size(); i++)
    {
        if (groupedIds[i].size() > maxCount)
        {
            maxCount = groupedIds[i].size();
            maxIdx = i;
        }
    }

    if (maxCount == 0)
    {
        cout << "NIE";
    }
    else
    {
        cout << maxCount << endl;
        for (int id : groupedIds[maxIdx])
        {
            cout << id << ' ';
        }
    }
}

int main()
{
    readData();
    stripNet();
    groupAndCount();

    return 0;
}