#include <iostream>
#include <fstream>
#include <cmath>
#include <vector>
#include <queue>
#include <deque>
#include <list>
#include <string>
#include <algorithm>
using namespace std;
ifstream ff("dfs.in");
ofstream gg("dfs.out");
#define max 100001

int n, m, k;
vector<int> vv[max];
bool ww[max];

void dfs(int x){
	int y, l;
	ww[x]=1;
	l=vv[x].size();
	for(int i=0;i<l;i++){
		y=vv[x][i];
		if(!ww[y])dfs(y);
	}
}

int main(){
	int x, y;
	ff >> n >> m;
	for(int i=0;i<m;i++){
		ff >> x >> y;
		vv[x].push_back(y);
		vv[y].push_back(x);
	}
	for(int i=1;i<=n;i++)
	if(!ww[i]){ dfs(i); k++; }
	cout << k;
	return 0;
}