112824

#include <iostream>
//#include <chrono>
//#include <fstream>
//#include <bits/stdc++.h>
#include <vector>
#include <algorithm>

#define mp make_pair
#define pb push_back
#define eb emplace_back
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)

using namespace std;

typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;

int count_bridge = 0;
int timer = 0;
int n, m;
vector<vector<bool>> vec;
vector<int> tin;
vector<int> fup;
vector<bool> used;

void dfs(int cur_v, int p) {
    used[cur_v] = true;
    fup[cur_v] = tin[cur_v] = timer++;
    for (int i = 0; i < n; i++) {
        if (i == p) continue;
        if (vec[cur_v][i] && used[i]) fup[cur_v] = min(fup[cur_v], tin[i]);
        else if (vec[cur_v][i]) {
            dfs(i, cur_v);
            fup[cur_v] = min(fup[cur_v], fup[i]);
            if (fup[i] > tin[cur_v])
                count_bridge++;
        }
    }

}

int main() {
    /*ifstream cin("in.txt");
    ofstream cout("out.txt");
    auto start_time = chrono::high_resolution_clock::now();*/

    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);

    cin >> n >> m;
    vec.assign(n, vector<bool>(n));
    tin.assign(n, 0);
    fup.assign(n, 0);
    used.assign(n, false);
    for (int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;
        vec[--a][--b] = true;
        vec[b][a] = true;
    }
    for (int i = 0; i < n; i++)
        if (!used[i])
            dfs(i, -1);
    cout << m - count_bridge << "\n";

    /*auto end_time = chrono::high_resolution_clock::now();
    chrono::duration<double> duration = end_time - start_time;
    cout << duration.count() << "\n";
    cin.close();
    cout.close();*/
    return 0;
}