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#include <cstdlib>
#include <iostream>
#include <vector>
#include <cmath>
#include <numeric>
#include <string>
#include <queue>
#include <set>
#include <map>
#include <unordered_set>

class World {
private:
    unsigned int d;
    std::vector<std::vector<int> > paths;
    std::vector<unsigned int> ranks;
    std::vector<bool> removed;
private:

    void readInput() {
        int n, m, d;
        std::cin >> n >> m>>d;
        this->d = d;
        paths.resize(n);
        ranks.resize(n);
        removed.resize(n);
        for (int i = 0; i < m; ++i) {
            int a, b;
            std::cin >> a>>b;
            a--;
            b--;
            paths[a].push_back(b);
            paths[b].push_back(a);
            ranks[a]++;
            ranks[b]++;
        }
    }
    
    void removeNotConnected() {
        std::queue<int> toRemove;
        for(unsigned int i = 0; i < ranks.size(); ++i) {
            if(ranks[i] < d) {
                toRemove.push(i);
            }
        }
        
        while(!toRemove.empty()) {
            int next = toRemove.front();
            toRemove.pop();
            if(removed[next]) {
                continue;
            }
            removed[next] = true;
            for(auto connected = paths[next].begin(); connected != paths[next].end(); ++connected) {
                ranks[*connected]--;
                if(ranks[*connected] < d) {
                    toRemove.push(*connected);
                }
            }            
        }
    }
    
    std::set<int> findSolution() {
        std::set<int> solution;
        std::set<int> toVisit;
        for(unsigned int i = 0; i < paths.size(); ++i) {
            if(!removed[i]) {
                toVisit.insert(i);
            }
        }
        
        while(!toVisit.empty()) {
            std::set<int> sol;
            int first = *toVisit.begin();
            std::queue<int> q;
            q.push(first);
            while(!q.empty()) {
                int next = q.front();
                q.pop();
                toVisit.erase(next);
                if(removed[next]) {
                    continue;
                }
                sol.insert(next);
                removed[next] = true;
                for(auto connected = paths[next].begin(); connected != paths[next].end(); ++connected) {
                    if(!removed[*connected]) {
                        q.push(*connected);
                    }
                }
            }
            
            if(sol.size() > solution.size()) {
                solution = sol;
            }
        }
        
        return solution;
    }

public:

    void solve() {
        readInput();
        removeNotConnected();
        std::set<int> solution = findSolution();
        if (solution.empty()) {
            std::cout << "NIE" << std::endl;
        } else {
            std::cout << solution.size() << std::endl;
            for (auto item = solution.begin(); item != solution.end(); ++item) {
                if (item != solution.begin()) {
                    std::cout << " ";
                }
                std::cout << (*item) + 1;
            }
            std::cout << std::endl;
        }
    }
};

int main(int argc, char** argv) {
    std::ios_base::sync_with_stdio(false);
    World world;
    world.solve();
    return 0;
}