#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
using namespace std;

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

vector<int> a[100005];
int v[100005], n, m, cnt;

void DFS(int k)
{
	if (v[k]) return;
	v[k] = 1;
	for (int e : a[k])
		DFS(e);
}

int main()
{
	int i, j;

	fin >> n >> m;
	while (m--)
	{
		fin >> i >> j;
		a[i].push_back(j);
		a[j].push_back(i);
	}

	for (i = 1; i <= n; i++)
		if (!v[i])
		{
			DFS(i);
			cnt++;
		}

	fout << cnt << "\n";
	return 0;
}