#include <iostream>
#include <stdio.h>

vector <int> t_1;
vector <int> t_2;
int time_ = 0;

int dfs(int v, vector <vector <int>> &g, vector <int> &visited, int count)
{
    int p = -1;
    visited[v] = 1; //vertex has visited

    t_1[v] = t_2[v] = time_++;

    for (int i = 0; i < g[v].size(); i++)
    {
        int cur = /*...*/; //current vertex

        if (cur == p) continue;

        if (visited[cur]) t_2[v] = min(t_2[v], t_1[cur]);

        else
        {
            dfs_rec(cur, g, visited, count);
            t_2[v] = min(t_2[v], t_2[cur]);

            if (t_1[v] < t_2[cur]) count++;
        }
    }

    return count;
}

void dfs(int v, vector <vector <int>> &g, vector <int> &visited, int count)
{
    int p = -1;
    visited[v] = 1; //vertex has visited

    t_1[v] = t_2[v] = time_++;

    for (int i = 0; i < g[v].size(); i++)
    {
        int cur = /*...*/; //current vertex

        if (cur == p) continue;

        if (visited[cur]) t_2[v] = min(t_2[v], t_1[cur]);

        else
        {
            dfs(cur, g, visited, count);
            t_2[v] = min(t_2[v], t_2[cur]);
        }
    }
}

int main()
{
    vector <vector <int>> g;
    vector <int> visited; //1 - visited, 0 - not visited;

    int n, m;
	cin >> n; //vertexes
	cin >> m; //edges

    g.resize(n);
    visited.resize(n);
    t_1.resize(n);
    t_2.resize(n);

	int u, v, count = 0;

	for (int i = 0; i < m; i++)
	{
		cin >> u; //v_1
		cin >> v; //v_2

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

	for (int i = 0; i < n; i++) visited[i] = 0;

    for (int i = 0; i < n; i++)
    {
        if (visited[i] == 0)
            dfs(i, g, visited, count);
    }

    cout << count;

	return 0;
}