#include<bits/stdc++.h>

using namespace std;


int viz[100100];
int n,m,x,y,k=0;
vector <int> a[100100];


void dfs(int nod){
	viz[nod]=1;
	for(int i=0;i<a[nod].size();i++)
		if(!viz[a[nod][i]])
			dfs(a[nod][i]);
}


int main(){
	ifstream cin("dfs.in");
	ofstream cout("dfs.out");
	cin>>n;
	cin>>m;
	for(int i=1;i<=m;i++){
		cin>>x>>y;
		a[x].push_back(y);
		a[y].push_back(x);
	}
	for(int i=1;i<=n;i++) 
		if (!viz[i]){ 
			dfs(i);
			k++; 
		}
	
	cout<<k;
	return 0;
}