# pragma GCC optimize("Ofast")
# pragma GCC optimization ("unroll-loops")
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define forn(i,a,b) for (int i = a; i <= b; i++)
#define fi(i,a,b) for (int i = a; i < b; i++)
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define rc(s) return cout<<s,0
#define er erase
#define in insert
#define pi pair <int, int>
#define pii pair <pi, pi>
# define sz(x) (int)((x).size())
vector<int>v[100005];
int viz[100005],m,n,ans=0;
void dfs(int nod){
	viz[nod]=1;
	for(auto it:v[nod]){
		if(!viz[it])dfs(it);
	}
}


int32_t main(){
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	ifstream cin("dfs.in");
	ofstream cout("dfs.out");
	cin>>n>>m; int x,y;
	forn(k,1,m){
		cin>>x>>y;
		v[x].pb(y);
		v[y].pb(x);
	}
	forn(i,1,n){
		if(!viz[i]){
			ans++;
			dfs(i);
			
		}
	}
	cout<<ans;
return 0;
}