#include <iostream>
#include <vector>
#include <fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<vector<int>> matrice(100001);
vector<bool> vizitat(100001);
void DFS(int nod)
{
	vizitat[nod] = 1;
	for (int i = 0; i < matrice[nod].size(); i++)
	{
		if (!vizitat[matrice[nod][i]])
			DFS(matrice[nod][i]);
	}
}
int main()
{
	int noduri, muchii,nr=0;
	f >> noduri >> muchii;
	for (int i = 0; i < muchii; i++)
	{
		int x, y;
		f >> x >> y;
		matrice[x].push_back(y);
		matrice[y].push_back(x);
	}
	for (int i = 1; i <=noduri; i++)
	{
		if (!vizitat[i])
		{
			nr++;
			DFS(i);
		}
	}
	g << nr;
	return 0;
}