#include <stdio.h>
#define DIM 100005
struct nod {int x;
            nod *urm;} *lst[DIM];
int n,m;
int viz[DIM];
void add (int a,int b)
{
    nod *p=new nod;
    p->x=b;
    p->urm=lst[a];
    lst[a]=p;
}
void read ()
{
    int i,x,y;
    scanf ("%d%d",&n,&m);
    for (i=1; i<=m; ++i)
    {
        scanf ("%d%d",&x,&y);
        add (x,y);
        add (y,x);
    }

}
void df (int start)
{
    nod *p;
    viz[start]=1;
    for(p=lst[start];p;p=p->urm)
        if(viz[p->x]==0)
            df(p->x);
}
int main ()
{
    freopen ("dfs.in","r",stdin);
    freopen ("dfs.out","w",stdout);
    read ();
    int kontor=0;
    for(int i=1;i<=n;++i)
        if(viz[i]==0)
            df (i),++kontor;
    printf("%d",kontor);
    return 0;
}