///huynhocute123///
#include<bits/stdc++.h>
using namespace std;
#define S second
#define F first
#define pii pair<int,int>
#define piii pair<int,pair<int,int>>
#define pb push_back
#define pi M_PI
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = b; i >= a; --i)
#define ALL(v) v.begin(),v.end()
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
//random_device rd;
//mt19937 rng(rd());
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
//#define int long long
const int maxN = 1e5 ;
const int modd = 1e9 + 7;
const int base = 2309;
const int MAX = 1e9+9;
void minimize(int &u, int v){
if(v < u) u = v;
}
void maximize(int &u, int v){
if(v > u) u = v;
}
int n, k, t, m, res, a[maxN], low[maxN], nu[maxN], cnt, ck[maxN];
int l, r;
bool vis[maxN];
vector<int> e[maxN], adj[maxN];
vector<pii> bri;
void dfs(int u,int p ){
nu[u] = low[u]= ++cnt;
for(auto x : e[u]){
if(x == p)continue;
if(nu[x]){
minimize(low[u], nu[x]);
}else{
dfs(x, u);
minimize(low[u], low[x]);
if(low[x] == nu[x]){
adj[u].pb(x);
adj[x].pb(u);
ck[x] =1;
ck[u] =1;
}
}
}
}
void dfs2(int u ,int p){
int ct = 0;
// cout << u << " ";
for(auto x : adj[u]){
if(x == p)continue;
vis[x] =1;
// cout << x << " ";
ct=1;
dfs2(x, u);
// maximize(k, max(ct- 1, 1))
}
// cout <<ct;
if(ct == 0)++k;
}
void solve(){
cin >> n >> m;
FOR(i ,1 , m){
cin >> l >> r;
e[l].pb(r);
e[r].pb(l);
}
FOR(i, 1, n){
if(!nu[i])dfs(i,0);
}
FOR(i ,1 , n){
if(!vis[i] && ck[i] ==1 ){
k =0;
vis[i] =1;
dfs2(i, 0);
if(adj[i].size() == 1)k++;
// cout << k << " ";
res += (k + 1 )/2;
// res +=k;
}
}
cout <<res;
// for(auto [x,y] : bri){
// cout << x << " " << y <<'\n';
// }
// cout << bri.size();
}
signed main(){
// freopen("name.inp","r",stdin);
// freopen("name.out","w",stdout);
ios_base::sync_with_stdio(false);
cin.tie(0);
inp("task.inp");
t = 1;
// cin >> t;
while( t-- )solve();
}
