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

using namespace std;

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

vector <int> a[100010];
int n, m, x, y, viz[100010], ans;;

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



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

	for (int i = 1; i <= n; i++)
	{
		if (viz[i] == 0)
		{
			ans++;
			dfs(i);
		}
	}

	out << ans;
	return 0;
}