#include<fstream>
#include<vector>
using namespace std;
int n,m,viz[100001],i,nr,x,y;
vector<int> a[100001];
void df(int vf)
{
	viz[vf]=1;
	int size=a[vf].size();
	for(int i=0;i<size;i++)
		if(!viz[a[vf][i]])
			df(a[vf][i]);
}
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++;
			df(i);}
	g<<nr;
	g.close();
}