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#include <cstdio>
#include <vector>
#include <set>
#include <algorithm>
#include <queue>
#include <string.h>

using namespace std;

struct Node {
    int id;
    int connectionsCount;

    bool operator()(const Node *lhs, const Node *rhs) const {
        if (lhs->connectionsCount != rhs->connectionsCount)
            return lhs->connectionsCount < rhs->connectionsCount;
        return lhs->id < rhs->id;
    }
};

int bfs(const vector<int> graph[], bool alive[], int colors[], int start, int color);

int main() {
    int n, m, d;
    scanf("%d%d%d", &n, &m, &d);

    vector<int> graph[n];
    bool alive[n];
    memset(alive, 0, sizeof(alive));
    Node *nodesT[n];

    for (int i = 0; i < m; i++) {
        int a, b;
        scanf("%d%d", &a, &b);
        graph[a - 1].push_back(b - 1);
        graph[b - 1].push_back(a - 1);
    }

    set<Node *, Node> nodesS;
    for (int i = 0; i < n; i++) {
        nodesT[i] = new Node();
        nodesT[i]->id = i;
        nodesT[i]->connectionsCount = (int) graph[i].size();
        if (nodesT[i]->connectionsCount > 0)
            alive[i] = true;
        nodesS.insert(nodesT[i]);
    }

    while (!nodesS.empty()) {
        Node *first = *nodesS.begin();
        if (first->connectionsCount >= d)
            break;
        nodesS.erase(first);
        alive[first->id] = false;
        for (int i = 0; i < graph[first->id].size(); i++) {
            int target = graph[first->id][i];
            Node *node = nodesT[target];
            if (alive[node->id]) {
                Node *reference = *nodesS.find(node);
                nodesS.erase(reference);
                node->connectionsCount--;
                nodesS.insert(node);
            }
        }
    }

    int colors[n];
    memset(colors, 0, sizeof(colors));

    int currentColor = 1;

    int bestColor = 0;
    int bestCount = 0;
    for (int i = 0; i < n; i++) {
        if (alive[i]) {
            int count = bfs(graph, alive, colors, i, currentColor);
            if (bestCount < count) {
                bestColor = currentColor;
                bestCount = count;
            }
            currentColor++;
        }
    }

    if (bestColor == 0) {
        printf("NIE\n");
        return 0;
    }

    printf("%d\n", bestCount);
    for (int i = 0; i < n; i++)
        if (colors[i] == bestColor)
            printf("%d ", i + 1);
    printf("\n");

    return 0;
}

int bfs(const vector<int> graph[], bool alive[], int colors[], int start, int color) {
    int count = 0;
    queue<int> Q;
    Q.push(start);
    while (!Q.empty()) {
        int id = Q.front();
        Q.pop();
        count++;
        colors[id] = color;
        alive[id] = false;
        for (int i = 0; i < graph[id].size(); i++) {
            int target = graph[id][i];
            if (alive[target]) {
                Q.push(target);
                alive[target] = false;
            }
        }
    }
    return count;
}