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#include <cstdio>
#include <vector>

using namespace std;

const int MAX_N = 200000;

vector<int> adj[MAX_N + 1];
int deg[MAX_N + 1];
bool deleted[MAX_N + 1];
int visited[MAX_N + 1];
int component[MAX_N + 1];
int component_cnt[MAX_N + 1];
int heap[MAX_N];
int heap_size = 0;
int heap_pos[MAX_N + 1];

inline int parent(int i) {
    return i / 2;
}

inline int left(int i) {
    return i * 2;
}

inline int right(int i) {
    return (i * 2) + 1;
}

void heapify(int i) {
    int smallest = i;
    int l = left(i);
    int r = right(i);
    if ((l < heap_size) && (deg[heap[l]] < deg[heap[smallest]])) smallest = l;
    if ((r < heap_size) && (deg[heap[r]] < deg[heap[smallest]])) smallest = r;
    if (smallest != i) {
        heap_pos[heap[i]] = smallest;
        heap_pos[heap[smallest]] = i;
        int tmp = heap[i];
        heap[i] = heap[smallest];
        heap[smallest] = tmp;
        heapify(smallest);
    }
}

void build_heap(int n) {
    heap_size = n;
    for (int i = 0; i < n; i++) {
        heap[i] = i + 1;
        heap_pos[i + 1] = i;
    }
    for (int i = n / 2; i >= 0; i--) heapify(i);
}

int extract_min() {
    int res = heap[0];
    heap[0] = heap[--heap_size];
    heap_pos[heap[0]] = 0;
    heapify(0);
    return res;
}

bool empty() {
    return !(heap_size > 0);
}

void decrease_key(int i) {
    while ((i > 0) && (deg[heap[parent(i)]] > deg[heap[i]])) {
        heap_pos[heap[i]] = parent(i);
        heap_pos[heap[parent(i)]] = i;
        int tmp = heap[i];
        heap[i] = heap[parent(i)];
        heap[parent(i)] = tmp;
        i = parent(i);
    }
}

void dfs_visit(int u, int curr_component) {
    visited[u] = true;
    component[u] = curr_component;
    for (int i = 0; i < adj[u].size(); i++) {
        int v = adj[u][i];
        if ((!deleted[v]) && (!visited[v])) {
            dfs_visit(v, curr_component);
        }
    }
}

void dfs(int n) {
    for (int u = 1; u <= n; u++) {
        visited[u] = false;
        component[u] = 0;
    }
    int curr_component = 0;
    for (int u = 1; u <= n; u++) {
        if ((!deleted[u]) && (!visited[u])) {
            curr_component += 1;
            dfs_visit(u, curr_component);
        }
    }
}

int main() {
    int n, m, d;
    scanf("%d%d%d", &n, &m, &d);
    for (int i = 1; i <= n; i++) {
        deg[i] = 0;
        deleted[i] = false;
    }
    for (int i = 0; i < m; i++) {
        int a, b;
        scanf("%d%d", &a, &b);
        deg[a] += 1;
        deg[b] += 1;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    build_heap(n);
    int min_deg = extract_min();
    while ((!empty()) && (deg[min_deg] < d)) {
        // printf("Deleting %d (%d)\n", min_deg, deg[min_deg]);
        deleted[min_deg] = true;
        for (int i = 0; i < adj[min_deg].size(); i++) {
            deg[adj[min_deg][i]] -= 1;
            decrease_key(heap_pos[adj[min_deg][i]]);
        }
        min_deg = extract_min();
    }
    if (empty()) {
        printf("NIE\n");
    }
    else {
        dfs(n);
        for (int i = 1; i <= n; i++) component_cnt[i] = 0;
        for (int u = 1; u <= n; u++) {
            if (component[u]) {
                component_cnt[component[u]]++;
            }
        }
        int res = 0;
        int res_component;
        for (int i = 1; i <= n; i++) {
            if (component_cnt[i] > res) {
                res = component_cnt[i];
                res_component = i;
            }
        }
        printf("%d\n", res);
        int i = 0;
        for (int u = 1; u <= n; u++) {
            if (component[u] == res_component) {
                i++;
                if (i == res) printf("%d\n", u);
                else printf("%d ", u);
            }
        }
    }

    return 0;
}