#include<fstream>
#include<vector>
using namespace std;
const int MAXN=100010;
vector<int> v[MAXN];
bool trecut[MAXN];
int n,m,nrconexe=0;
void citire()
{
	int x,y,i;
	ifstream fin("dfs.in");
	fin>>n>>m;
	for (i=1;i<=m;++i)
	{
		fin>>x>>y;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	fin.close();
}
void dfs_visit(int start)
{
	trecut[start]=true;
	for (vector<int>::iterator it=v[start].begin();it!=v[start].end();++it)
		if (!trecut[*it])			//daca nu am mai trecut
			dfs_visit(*it);
}
void dfs()
{
	int i;
	for (i=1;i<=n;++i)
	{
		if (!trecut[i])
		{
			nrconexe++;
			dfs_visit(i);
		}
	}
}
void afisare()
{
	ofstream fout("dfs.out");
	fout<<nrconexe<<'\n';
	fout.close();
}
int main()
{
	citire();
	dfs();
	afisare();
	return 0;
}