#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
#include <string.h>
#include <stdio.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int MAXN = 100005;

int n, m, x, y, answer;
vector <int> d[MAXN];

bool viz[MAXN];

void read(){
	fin >> n >> m;
	for(int i = 0; i < m; ++i){
		fin >> x >> y;
		d[x].push_back(y);
		d[y].push_back(x);
	}
     fin.close();
}

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

void show(){
	fout << answer <<"\n";
}

int main(){
	read();
  memset(viz, false, sizeof(viz));
	for(int i = 1; i <= n; i++){
    if(!viz[i]){
        answer +=1;
        dfs(i);
    }
	}
	show();
	return 0;
}