#include <bits/stdc++.h> //JuniorMonster a.k.a Sho10
#define ll long long
#define all(a) (a).begin(), (a).end()
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define sz size
#define f first
#define s second
#define pb push_back
#define er erase
#define in insert
#define mp make_pair
#define pi pair
#define rc(s) return cout<<s,0
#define mod 1000000007
#define PI 3.14159265359
using namespace std;
ll n,m,x,y,viz[100005],ans;
vector<ll>v[100005];
void dfs(ll x){
    viz[x]=1;
for(ll i=0;i<v[x].size();i++)
if(viz[v[x][i]]==0){
    dfs(v[x][i]);
}
}
int32_t main(){
    ifstream cin("dfs.in");
    ofstream cout("dfs.out");
    cin>>n;
    cin>>m;
    for(ll i=0;i<m;i++){
        cin>>x;
        cin>>y;
        v[x].pb(y);
        v[y].pb(x);
    }
    for(ll i=0;i<n;i++)
    if(viz[i+1]==0){
        ans++;
        dfs(i+1);
    }
    cout<<ans<<endl;
}