#include<fstream>
#include<list>
#define NMAX 100005

using namespace std;

list<int> a[NMAX];
int n, m, i, x, y, nr=0, viz[NMAX];

void DFS(int nod)
{
	list<int>:: iterator it;
	viz[nod]=1;
	for(it=a[nod].begin(); it!=a[nod].end(); ++it)
		if (!viz[*it]) DFS(*it);
}

int main()
{
	ifstream f("dfs.in");
	ofstream g("dfs.out");
	
	f>>n>>m;
	for (i=1; i<=m; ++i)
	{
		f>>x>>y;
		a[x].push_back(y);
		a[y].push_back(x);
	}
	
	for(i=1; i<=n; ++i)
		if (!viz[i])
		{
			++nr;
			DFS(i);
		}
	g<<nr<<"\n";
	f.close();
	g.close();
	return 0;
}