#include<iostream.h>
#include<fstream.h>
int viz[100001],n;
struct nod 
{int y;     
nod *next;};
nod *v[100005];  
void add(nod*&dest, int y) 
{nod *p;
p = new nod; 
p -> y = y; 
p->next=dest;
dest=p;}	
void parcurg(int x)
{nod*p;
	viz[x]=1;
	for(p=v[x];p!=NULL;p=p->next)
		if(viz[p->y]==0)
			parcurg(p->y);}
int main()
{ifstream f("dfs.in");
ofstream h("dfs.out");
	int i,m,x,y,cnt=0;
	f>>n>>m;
for(i=1;i<=m;i++)
	{f>>x>>y;
add(v[x],y);
add(v[y],x);}
	for(i=1;i<=n;i++)
	if(viz[i]==0)
		{cnt++;
		parcurg(i);}
		h<<cnt;
return 0;}