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#include <iostream>
#include <set>

using namespace std;

set <int> v[200005];
set <int> del, del_e[200005];
set <int> bfs_out, bfs;

bool odw[200005];

int main(){
    int n, m, k;

    cin >> n >> m >> k;

    for(int i=0;i<m;i++){
        int a, b;
        cin >> a >> b;
        v[a].insert(b);
        v[b].insert(a);
    }
    for(int i=1;i<n+1;i++){
        if(v[i].size()<k){
            for(set<int>::iterator it=v[i].begin(); it!=v[i].end(); ++it){
                del.insert(*it);
                del_e[*it].insert(i);
            }
            v[i].clear();
        }
    }
    while(!del.empty()){
        int act = *del.begin();
        del.erase(del.begin());
        while(!del_e[act].empty()){
            v[act].erase(*del_e[act].begin());
            del_e[act].erase(del_e[act].begin());
        }
        if(v[act].size()<k){
            for(set<int>::iterator it=v[act].begin(); it!=v[act].end(); ++it){
                del.insert(*it);
                del_e[*it].insert(act);
            }
        }
    }

    set <int> max_v;
    for(int i=1;i<n+1;i++){
        if(odw[i]==0&&!v[i].empty()){
            bfs.insert(i);
            odw[i] = 1;
            while(!bfs.empty()){
                int act = *bfs.begin();
                bfs_out.insert(act);
                bfs.erase(bfs.begin());
                for(set<int>::iterator it=v[act].begin(); it!=v[act].end(); ++it){
                    if(odw[*it]==0){
                        odw[*it] = 1;
                        bfs.insert(*it);
                    }
                }
            }
            if(max_v.size()<bfs_out.size())
                max_v.swap(bfs_out);
            bfs_out.clear();
        }
    }
    if(max_v.empty())
        cout << "NIE";
    else{
        cout << max_v.size() << "\n";
        for(set<int>::iterator it=max_v.begin(); it!=max_v.end(); ++it)
            cout << *it << " ";
    }

    return 0;
}