#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

#define vi vector <int>
#define vit vector <int> :: iterator
#define vii vector <pair <int, int> >
#define viit vector <pair <int, int> > :: iterator

ifstream f("dfs.in"); ofstream g("dfs.out");

int i, j, n, m, x, y, k;
vi graph[111111];
bool viz[111111];

void dfs(int node){
	viz[node]=1;
	for (vit it=graph[node].begin(); it!=graph[node].end(); it++){
		if (!viz[*it]) dfs (*it);
	}
}

int main(){
	f>>n>>m;
	for (i=1; i<=m; i++){
		f>>x>>y;
		graph[x].push_back(y);
		graph[y].push_back(x);
	}
	
	for (i=1; i<=n; i++){
		if (!viz[i]){
			dfs(i);
			k++;
		}
	}
	g<<k;
	
}