#include <iostream>
#include <vector>

using namespace std;

const int MAX_N = 300005;

int bridgec;
vector<int> adj [MAX_N];

int lvl [MAX_N];
int dp [MAX_N];

void visit (int vertex) {
	dp[vertex] = 0;
	vector<int> temp;
	int par = 0;
	int child = 0;
	for (int nxt : adj[vertex])
	{
		if (lvl[nxt] == 0)
		{	/* edge to child */
			child++;
			if (!temp.empty())
			{
				temp[temp.size() - 1] -= par;
				par = 0;
			}
			lvl[nxt] = lvl[vertex] + 1;
			visit(nxt);
			dp[vertex] += dp[nxt];
			temp.push_back(dp[nxt]);
		}
		else if (lvl[nxt] < lvl[vertex])
		{	/* edge upwards */
			dp[vertex]++;
		}
		else if (lvl[nxt] > lvl[vertex])
		{	/* edge downwards */
			dp[vertex]--;
			par++;
		}

	}
	/* the parent edge isn't a back-edge, subtract 1 to compensate */
	dp[vertex]--;

	//Special Cases
	if (child == 0)
		return;//leave node
	if (vertex == 1)
	{
		// root node
		if (child > 1)
		{
			cout << "vertex " << vertex << endl;
			bridgec++;
		}
		return;
	}

	//General Cases
	temp[temp.size() - 1] -= par;
	int flag = 0;
	for (int x : temp)
	{
		if (x != 0) continue;
		else {
			flag = 1;
		}
	}
	if (flag)
	{
		cout << "vertex " << vertex << endl;
		bridgec++;
	}
}

int main () {
	/* problem statement: given a connected graph. calculate the number of articulation points. */
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#ifndef ONLINE_JUDGE
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
#endif
	int vertexc, edgec;
	cin >> vertexc >> edgec;

	for (int i = 0; i < edgec; i++) {
		int u, v;
		cin >> u >> v;

		adj[u].push_back(v);
		adj[v].push_back(u);
	}

	lvl[1] = 1;
	visit(1);
	cout << bridgec << endl;
}