/*
        By: facug91
        From:
        Name:
        Date: 23/09/2015
*/

#include <bits/stdc++.h>
#define y1      nd03dnqwuidg1odbnw9uddu0132d
#define clock   asoudh219udhjdgausdhs9udy433
#define left    dfgag34gsfaf342rf23fgwrf42ff
#define middle  lk78k6ujkj76kjk88kkummnhh456
#define right   apidwcojbl213f80sjb3y8efjfas
#define move    df53y5fgsf43fdsfsdtg4j6hfdg4
#define count   nkwdfj111afbjdfsbj32r8yfwejb
#define prev    asdnklgbgbjfasdbhksdva4t9jds
#define endl "\n"
#define EPS 1e-9
#define MP make_pair
#define DB(x) cerr << " #" << (#x) << ": " << (x)
#define DBL(x) cerr << " #" << (#x) << ": " << (x) << endl
const double PI = 2.0*acos(0.0);

#define INF 1000000000
//#define MOD 1000000007ll
//#define MAXN 10005

using namespace std;
typedef long long ll;
typedef unsigned long long llu;
typedef pair<int, int> ii; typedef pair<ii, ii> iiii;
typedef vector<int> vi; typedef vector<ii> vii; typedef vector<iiii> viiii;

int n, q, a, b, s, t, p[405], pa[405], cnt;
vector<pair<int, pair<int, int> > > adj[405], adj2[405];
bool vis[405];

bool bfs () {
    int u, v, c, rev, i;
    queue<int> q; q.push(s);
    for (i=1; i<=n; i++) p[i] = pa[i] = -1;
    bool sink = false;
    while (q.size()) {
        u = q.front(); q.pop();
        if (u == t) {
            sink = true;
            continue;
        }
        for (i=0; i<adj[u].size(); i++) {
            v = adj[u][i].first;
            c = adj[u][i].second.first;
            rev = adj[u][i].second.second;
            if (p[v] == -1 && c > 0) {
                p[v] = u;
                pa[v] = rev;
                q.push(v);
            }
        }
    }
    return sink;
}
int dfs (int u, int min_edge) {
    if (u == s) return min_edge;
    else if (p[u] != -1) {
        int rev = adj[u][pa[u]].second.second;
        int cr = adj[p[u]][rev].second.first;
        if (cr > 0) {
            int f = dfs(p[u], min(min_edge, cr));
            if (f) {
                adj[p[u]][rev].second.first -= f;
                adj[u][pa[u]].second.first += f;
            }
            return f;
        } else return 0;
    } else return 0;
}

int max_flow () {
    int mf = 0, i, v, cr, rev;
    while (bfs()) {
        for (i=0; i<adj[t].size(); i++) {
            v = adj[t][i].first;
            rev = adj[t][i].second.second;
            cr = adj[v][rev].second.first;
            if (cr > 0) {
                p[t] = v;
                pa[t] = i;
                mf += dfs(t, cr);
            }
        }
    }
    return mf;
}

void count_component (int u) {
    vis[u] = true;
    cnt++;
    for (int i=0; i<adj[u].size(); i++) {
        int v = adj[u][i].first;
        if (!vis[v]) count_component(v);
    }
}

int main () {
    ios_base::sync_with_stdio(0); cin.tie(0);
    //cout<<fixed<<setprecision(7); cerr<<fixed<<setprecision(7); //cin.ignore(INT_MAX, ' '); //cout << setfill('0') << setw(5) << 25
    int i, j, tc;

    cin>>n>>q;
    while (q--) {
        cin>>a>>b; a--;
        adj[a].push_back(MP(b, MP(1, adj[b].size())));
        adj[b].push_back(MP(a, MP(0, adj[a].size()-1)));
        adj[a].push_back(MP(b, MP(0, adj[b].size())));
        adj[b].push_back(MP(a, MP(1, adj[a].size()-1)));
    }
    memset(vis, 0, sizeof vis);
    n++;
    cnt = 0;
    count_component(0);
    if (cnt < n) {
        cout<<0<<endl;
        return 0;
    }
    for (i=0; i<n; i++) adj2[i] = adj[i];
    int ans = INT_MAX;
    for (i=1; i<n; i++) {
        s = 0; t = i;
        for (j=0; j<n; j++) adj[j] = adj2[j];
        ans = min(ans, max_flow());
    }
    cout<<ans<<endl;

    return 0;
}