#include <iostream>
#include <fstream>
#include <vector>
#define Nlim 100005

using namespace std;

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

int N, M, viz[100005], insula;
vector <int> muchii[Nlim];

void DFS(int nod)
{
	viz[nod] = 1;
	for (unsigned int i = 0; i < muchii[nod].size(); i++)
	{
		int vecin = muchii[nod][i];
		if (!viz[vecin])
			DFS(vecin);
	}
}

int main()
{
	fin >> N >> M;

	for (int i = 1; i <= M; i++)
	{
		int x, y;
		fin >> x >> y;
		muchii[x].push_back(y);
		muchii[y].push_back(x);
	}
	
	for (int i = 1; i <= N; i++)
	{
		if (!viz[i])
		{
			++insula;
			DFS(i);
		}
	}
	fout << insula;
	return 0;
}