#include <iostream>
#include <vector>
#include <queue>
#include <fstream>

using namespace std;

int n, m, s, dist[100005], a, b, nr,viz[100005];
vector <int> v[100005];

void dfs(int nod) {
	viz[nod] = 1;
	for (int i = 0; i < v[nod].size(); i++)
		if (!viz[v[nod][i]]) dfs(v[nod][i]);
}

int main() 
{
	ifstream cin("dfs.in");
	ofstream cout("dfs.out");
	cin >> n >> m;
	for (int i = 1; i <= m; i++)
	{
		cin >> a >> b;
		v[a].push_back(b);
		v[b].push_back(a);
	}
	
	for (int i = 1; i <= n; i++)
		if (!viz[i]) dfs(i), nr++;

	cout << nr;
}