#include <set>
#include <map>
#include <vector>
#include <cstdio>
#include <algorithm>
using namespace std;
int n, m, d, a, b;
vector<set<int> > adj;
vector<int> component, curr_component, max_component;
void find_component(int v, int id)
{
component[v] = id;
curr_component.push_back(v);
for(set<int>::iterator it = adj[v].begin(); it!=adj[v].end(); ++it)
{
if (component[*it] != -1) continue;
find_component(*it, id);
}
}
int main()
{
scanf("%d %d %d", &n, &m, &d);
adj.resize(n);
for(int i=0; i<m; ++i)
{
scanf("%d %d", &a, &b); --a; --b;
adj[a].insert(b);
adj[b].insert(a);
}
vector<int> to_remove;
for(int i=0; i<n; ++i) if (adj[i].size() < d) to_remove.push_back(i);
while (!to_remove.empty())
{
int v = to_remove.back();
to_remove.pop_back();
for(set<int>::iterator it=adj[v].begin(); it!=adj[v].end(); ++it)
{
adj[*it].erase(v);
if (adj[*it].size() == d-1)
{
to_remove.push_back(*it);
}
}
adj[v].clear();
}
int max_id = -1;
component.resize(n, -1);
max_component.clear();
for(int i=0; i<n; ++i)
{
if (component[i] != -1) continue;
max_id += 1;
curr_component.clear();
find_component(i, max_id);
if (curr_component.size() > max_component.size()) max_component = curr_component;
}
if (max_component.size() < d) printf("NIE\n");
else
{
printf("%d\n", max_component.size());
sort(max_component.begin(), max_component.end());
for(int i=0; i<max_component.size(); ++i) printf("%d ", max_component[i]+1);
printf("\n");
}
}