#include <bits/stdc++.h>

using u32 = unsigned;
using i64 = long long;
using u64 = unsigned long long;

constexpr int N = 2E4 + 5;

int n, m;
int dfn[N], low[N], tot;
std::vector<int> adj[N];
bool cut[N];

void tarjan(int x, int fa) {

	dfn[x] = low[x] = ++tot;

	int deg = 0;

	for (auto v : adj[x]) {
		if (!dfn[v]) {
			tarjan(v, x);
			++deg;
			low[x] = std::min(low[x], low[v]);
			if (low[v] >= dfn[x] && !cut[v] && fa) cut[x] = 1;
		} else if (v != fa) {
			low[x] = std::min(low[x], dfn[v]);
		}
	}

	if (fa == 0 && deg > 1) cut[x] = 1;
}

int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);

	std::cin >> n >> m;

	for (int i = 1; i <= m; ++i) {
		int u, v;
		std::cin >> u >> v;
		adj[u].push_back(v);
		adj[v].push_back(u);
	}

	for (int i = 1; i <= n; ++i) {
		if (!dfn[i])
			tarjan(i, 0);
	}

	std::vector<int> ans;
	for (int i = 1; i <= n; ++i)
		if (cut[i]) ans.push_back(i);

	std::cout << ans.size() << "\n";
	for (auto x : ans)
		std::cout << x << " \n"[x == ans.back()];

	return 0;
}