#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<int, int> Pi;
typedef vector<ll> Vec;
typedef vector<int> Vi;
typedef vector<string> Vs;
typedef vector<P> VP;
typedef vector<vector<ll>> VV;
typedef vector<vector<int>> VVi;

#define REP(i, a, b) for(ll i=(a); i<(b); i++)
#define PER(i, a, b) for(ll i=(a); i>=(b); i--)
#define rep(i, n) REP(i, 0, n)
#define per(i, n) PER(i, n, 0)
const ll INF=1e18+18;
const ll MAX=100005;
const ll MOD=1000000007;
#define Yes(n) cout << ((n) ? "Yes" : "No") << endl;
#define YES(n) cout << ((n) ? "YES" : "NO") << endl;
#define ALL(v) v.begin(), v.end()
#define rALL(v) v.rbegin(), v.rend()
#define pb(x) push_back(x)
#define mp(a, b) make_pair(a,b)
#define Each(a,b) for(auto &a :b)
#define REPM(i, mp) for (auto i = mp.begin(); i != mp.end(); ++i)
#define dbg(x_) cerr << #x_ << ":" << x_ << endl;
#define dbgmap(mp) cerr << #mp << ":"<<endl; for (auto i = mp.begin(); i != mp.end(); ++i) { cerr << i->first <<":"<<i->second << endl;}
#define dbgarr(n,m,arr) rep(i,n){rep(j,m){cerr<<arr[i][j]<<" ";}cerr<<endl;}
#define dbgdp(n,arr) rep(i,n){cerr<<arr[i]<<" ";}cerr<<endl;
#define Uniq(v) v.erase(unique(v.begin(), v.end()), v.end())
#define fi first
#define se second

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return true; } return false; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return true; } return false; }

template<typename T1, typename T2>
ostream &operator<<(ostream &s, const pair<T1, T2> &p) { return s<<"("<<p.first<<", "<<p.second<<")"; }

// vector
template<typename T>
ostream &operator<<(ostream &s, const vector<T> &v) {
    int len=v.size();
    for(int i=0; i<len; ++i) {
        s<<v[i];
        if(i<len-1) s<<"	";
    }
    return s;
}

// 2 dimentional vector
template<typename T>
ostream &operator<<(ostream &s, const vector<vector<T> > &vv) {
    int len=vv.size();
    for(int i=0; i<len; ++i) {
        s<<vv[i]<<endl;
    }
    return s;
}

//int main() {
//    cin.tie(0);
//    ios::sync_with_stdio(false);
//    cout<<std::setprecision(10);
//
//    ll n,m;
//    cin>>n>>m;
//
//    ll ans=0;
//    VP edge(m);
//    rep(i,m){
//        ll a,b;
//        cin>>a>>b;
//        a--;b--;
//        edge[i]=mp(a,b);
//    }
//
//    rep(i,m){
//        VV dist(n,Vec(n,INF));
//        rep(j,n){
//            dist[j][j] = 0;
//        }
//        rep(j,m){
//           if(j==i)continue;
//            P &p = edge[j];
//            dist[p.fi][p.se] = dist[p.se][p.fi] = 1;
//        }
//        rep(k,n){
//            rep(a, n){
//                rep(b, n) {
//                    dist[a][b] = min(dist[a][b], dist[a][k]+dist[k][b]);
//                }
//            }
//        }
//        bool connect = true;
//        rep(a,n){
//            rep(b,n){
//                if(dist[a][b]>=INF){
//                    connect = false;
//                    goto chk;
//                }
//            }
//        }
//        chk:
//        if(!connect){
//            ans++;
//        }
//    }
//    cout<<ans<<endl;
//    return  0;
//}

ll n, m;
vector<bool> visited;

void dfs(ll x, VV &g){
    visited[x] = true;
    rep(nxt,n){
        if(g[x][nxt]==INF)continue;
        if(visited[nxt])continue;
        dfs(nxt,g);
    }
}

//dfs使ってみた
int main() {
    cin>>n>>m;
    ll ans = 0;
    visited.resize(n);
    VP edges(m);
    VV g(n,Vec(n,INF));
    rep(i,m){
        ll a,b;
        cin>>a>>b;
        a--;b--;
        g[a][b] = g[b][a] = 1;
        edges[i]=mp(a,b);
    }

    rep(i,m){
        P &p = edges[i];
        g[p.fi][p.se] = g[p.se][p.fi] = INF;
        rep(j,n){
            visited[j] = false;
        }
        dfs(0,g);
        bool connected = true;
        rep(j,n){
            connected &= visited[j];
        }
        if(!connected){
            ans++;
        }
        g[p.fi][p.se] = g[p.se][p.fi] = 1;
    }
    cout<<ans<<endl;
    return 0;
}


Measured memory_bytes: 256