#include <bits/stdc++.h>
using namespace std;
int n,x,y,m,k;
vector <int> v[100100];
bool viz[100100];
void dfs(int x){
	viz[x]=1;
	for (int j=0;j<v[x].size();j++){
		if (!viz[v[x][j]]){
			dfs(v[x][j]);
		}
	}
}
int main(){
	ifstream cin("dfs.in");
	ofstream cout("dfs.out");
	cin>>n>>m;
	for (int i=1;i<=m;i++){
		cin>>x>>y;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	for (int i=1;i<=n;i++){
		if (!viz[i]) {
			k++;
			dfs(i);	
		}
	}
	// dfs(1) 1 2 3 4 5 6 7(1 0 1 0 1 0 0)
	// dfs(2) 1 2 3 4 5 6 7(1 1 1 1 1 1 1)
	cout<<k;
	return 0;
}