#include<bits/stdc++.h>
using namespace std;
int N,M,viz[200005],ans=0,x,y;
vector<int>v[200005];
void dfs(int nod){
	viz[nod]=1;
	for(int i=0;i<v[nod].size();i++){
		if(!viz[v[nod][i]]){
			dfs(v[nod][i]);
		}
	}
}
int main(){
	ifstream in("dfs.in");
	ofstream out("dfs.out");
	in>>N>>M;
	for(int i=0;i<M;i++){
		in>>x>>y;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	for(int i=1;i<=N;i++){
		if(!viz[i]){
			ans++;
			dfs(i);
		}
	}
	out<<ans;
}