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

using namespace std;

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

int n, m, nrc;
vector <int> G[100001];
int viz[100001];

void dfs(int x)
{
	viz[x] = nrc;

	for (auto it : G[x])
		if (!viz[it])
			dfs(it);
}

int main()
{
	fin >> n >> m;
	for (int i = 1; i <= m; i++)
	{
		int x, y;
		fin >> x >> y;
		G[x].push_back(y);
		G[y].push_back(x);
	}

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

	fout << nrc;
	return 0;
}