// Problem: P2860 [USACO06JAN] Redundant Paths G
// Contest: Luogu
// URL: https://www.luogu.com.cn/problem/P2860
// Time Limit: 1000 ms
// Start Time:2024-07-29 19:11:07
//
// Powered by CP Editor (https://cpeditor.org)

#ifndef LOCAL
#include <bits/stdc++.h>
#define csf std::cerr.setstate(std::ios_base::failbit)
#define db(x)
#else
#include <algorithm>
#include <cmath>
#include <cstring>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <vector>
#define db(x) cerr << __FUNCTION__ << " L" << __LINE__ << " " << #x " = " << (x) << endl
#define csf
#endif
#define ll long long
#define f(x, y, z) for (ll x = (y); x <= (z); x++)
using namespace std;
inline ll read();
const ll INF = 0x3f3f3f3f3f3f3f3f, N = 1e5 + 10;

ll n, m;
vector<ll> h[N];
ll id, dfn[N], gbk[N];
bool isk[N];
ll stk[N], stp;
ll fr[N];
ll ans = 1; // 叶子个数(包含根)
void tarjan(ll x, ll fa = 0)
{
    ll double_edge = 1;
    dfn[x] = gbk[x] = ++id;
    isk[x] = 1;
    stk[++stp] = x;

    for (auto v : h[x])
    {
        if (v == fa && double_edge)
        {
            double_edge--;
            continue;
        }
        if (dfn[v] || v == fa)
        {
            if (isk[v])
                gbk[x] = min(gbk[x], dfn[v]);
        }
        else
        {
            tarjan(v, x);
            if (gbk[v] > dfn[x])
            {
                while (stk[stp] != v)
                {
                    fr[stk[stp]] = v;
                    isk[stk[stp]] = 0;
                    stp--;
                }
                fr[stk[stp]] = v;
                isk[stk[stp]] = 0;
                stp--;
            }
            else
                gbk[x] = min(gbk[x], gbk[v]); // add
        }
    }
}

struct edge
{
    ll x, y;
} a[N];
bool kkk[N];
void dfs(ll x = 1, ll fa = 0)
{
    bool leaf = 1;
    for (auto v : h[x])
    {
        // cerr << x << "->" << v << endl;
        if (v == fa)
            continue;
        dfs(v, x);
        leaf = 0;
    }
    ans += leaf;
}
signed main()
{
    csf;
    cin >> n >> m;
    f(i, 1, m)
    {
        ll x, y;
        cin >> x >> y;
        h[x].push_back(y);
        h[y].push_back(x);
        a[i] = {x, y};
    }
    f(i, 1, n) if (dfn[i] == 0)
        tarjan(i);
    f(i, 1, n)
    {
        if (fr[i] == 0)
        {
            fr[i] = 1;
        }
        h[i].clear();
    }

    f(i, 1, m)
    {
        if (fr[a[i].x] == fr[a[i].y])
            continue;
        h[fr[a[i].x]].push_back(fr[a[i].y]);
        h[fr[a[i].y]].push_back(fr[a[i].x]);
    }
    dfs();
    db(ans);
    cout << ceil(ans / 2.0);
    return 0;
}