#include <bits/stdc++.h>
using namespace std;
const int N = 100010;
const int M = N << 1;

//链式前向星
int e[M], h[N], idx, w[M], ne[M];
void add(int a, int b, int c = 0) {
    e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++;
}

int n, m, timestamp, tot;
int dfn[N], low[N], cut[N];

void tarjan(int u, int fa) {
    dfn[u] = low[u] = ++timestamp;
    int son = 0;

    for (int i = h[u]; ~i; i = ne[i]) {
        int j = e[i];
        if (!dfn[j]) {
            tarjan(j, fa);
            low[u] = min(low[u], low[j]);
            if (low[j] >= dfn[u] && u != fa) cut[u] = 1;
            if (u == fa) son++;
        }
        low[u] = min(low[u], dfn[j]);
    }

    //根节点单独讨论
    if (son >= 2 && u == fa) cut[u] = 1;
}

int main() {
    memset(dfn, 0, sizeof(dfn));
    memset(h, -1, sizeof(h));

    scanf("%d%d", &n, &m);
    while (m--) {
        int a, b;
        scanf("%d%d", &a, &b);
        add(a, b), add(b, a);
    }
    for (int i = 1; i <= n; i++)
        if (!dfn[i]) tarjan(i, i);

    for (int i = 1; i <= n; i++)
        if (cut[i]) tot++;

    printf("%d\n", tot);
    for (int i = 1; i <= n; i++)
        if (cut[i]) printf("%d ", i);
    return 0;
}