#include<stdio.h>
#include<vector>
#define nmax 200010
using namespace std;
int v[nmax];
vector<int> a[nmax];
int i,j,nod,n,m,c=0,x,y,aux;
void dfs(int nod)
{
int i,aux;
v[nod]=1;
aux=a[nod].size();
 for(i=0;i<aux;i++)
	 if(v[a[nod][i]]==0)
        dfs(a[nod][i]);

}
int main()
{
freopen("dfs.in","r",stdin);
freopen("dfs.out","w",stdout);
scanf("%d %d",&n,&m);
for(i=1;i<=m;i++)
{
scanf("%d %d",&x,&y);
a[x].push_back(y);
a[y].push_back(x);
}
for(i=1;i<=n;i++)
	v[i]=0;

for(i=1;i<=n;i++)
  if(v[i]==0) 
	  {    c++;
		  dfs(i);
         
      }
  printf("%d",c);
return 0;
}