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

using namespace std;

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

const int NLIM = 100005;

int N, M;
vector < int > Edge[NLIM];

bool beenThere[NLIM];
int answer;

void DFS(int Node)
{
	beenThere[Node] = true;
	for (unsigned int i = 0; i < Edge[Node].size(); i++)
	{
		int Next = Edge[Node][i];
		if (!beenThere[Next])
			DFS(Next);
	}
}

void Read()
{
	fin >> N >> M;
	for (int i = 1; i <= M; i++)
	{
		int x, y;
		fin >> x >> y;
		Edge[x].push_back(y);
		Edge[y].push_back(x);
	}
	for (int i = 1; i <= N; i++)
	{
		if (!beenThere[i])
		{
			answer += 1;
			DFS(i);
		}
	}
	fout << answer << "\n";
}

int main()
{
	Read();
	return 0;
}