#include<iostream>
#include<fstream>
using namespace std;
struct lista
	{int inf;
	lista *adr;}*v[100005],*p;
int n,m,x,y,i,viz[100005],k;
ifstream f("dfs.in");
ofstream g("dfs.out");
void DFS(int x)
	{viz[x]=1;
	for(lista*p=v[x];p!=NULL;p=p->adr)
		if(viz[p->inf]==0)
			DFS(p->inf);
	}
int main()
{f>>n>>m;
for(i=1;i<=m;i++)
	{f>>x>>y;
	p=new lista;
	p->inf=y;
	p->adr=v[x];
	v[x]=p;
	p=new lista;
	p->inf=x;
	p->adr=v[y];
	v[y]=p;
	}
for(i=1;i<=n;i++)
	if(viz[i]==0)
		{DFS(i);
		k++;}
g<<k;
return 0;
}