#include<fstream>
#include<vector>
using namespace std;
const int nmax=100005;
vector<int> v[nmax];
int viz[nmax],g[nmax];
int n,m;
void citire ()
{
	ifstream fin("dfs.in");
	int i,x,y;
	fin>>n>>m;
	for(i=1;i<=m;i++)
	{
		fin>>x>>y;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	for(i=1;i<=n;i++)
		g[i]=v[i].size();
	fin.close ();
}
void dfs(int nod)
{
	int i;
	viz[nod]=1;
	for(i=0;i<g[nod];i++)
		if(!viz[v[nod][i]])
			dfs(v[nod][i]);
}
int main ()
{
	citire();
	int i,k=0;
	for(i=1;i<=n;i++)
		if(!viz[i]) 
		{
			k++;
			dfs(i);
		}
	ofstream fout("dfs.out");
	fout<<k;
	fout.close();
	return 0;
}