//#include "pch.h"
#include <iostream>
#include <fstream>
#include <vector>
#include <climits>
#include <algorithm>
#include <string>
using	 namespace std;
using ll = long long int;
fstream f("dfs.in");
ofstream o("dfs.out");
int n, m, k;
vector<int> v[100005];
int x, y;
bool visited[100005];
int insule;
void dfs(int cv)
{
	visited[cv] = true;
	for (size_t i = 0; i < v[cv].size(); i++)
	{
		int vecin = v[cv][i];
		if (!visited[vecin])
		{
			dfs(vecin);
		}
	}
}

int main()
{
	f >> n >> m;
	for (size_t i = 0; i < m; i++)
	{
		f >> x >> y;
		v[x].push_back(y);
		v[y].push_back(x);
	}

	for (size_t i = 0; i < n; i++)
	{
		if (!visited[i])
		{
			dfs(i);
			insule++;
		}
	}
	o << insule;

}