#include<fstream>
#include<vector>
#define NMAX 100010

using namespace std;

int n, m, lg[NMAX], vz[NMAX];
vector<int> a[NMAX];

ifstream f("dfs.in");
ofstream g("dfs.out");

void Citeste()
{
	int i, x, y;
	f>>n>>m;
	for (i=1; i<=m; ++i)
	{
		f>>x>>y; ++lg[x]; ++lg[y];
		a[x].push_back(y);
		a[y].push_back(x);
	}
}

void DFS(int nod)
{
	int i;
	vz[nod]=1;
	for (i=0; i<lg[nod]; ++i)
		if (!vz[a[nod][i]]) DFS(a[nod][i]);
}

int numar_cc()
{
	int nr=0, nod;
	
	for (nod=1; nod<=n; ++nod)
		if (!vz[nod])
		{
			++nr;
			DFS(nod);
		}
	return nr;
}

int main()
{
	Citeste();
	g<<numar_cc()<<"\n";
	f.close();
	g.close();
	return 0;
}