#include <iostream>
#include <cstdio>
using namespace std;
FILE *f=fopen("dfs.in", "r");
FILE *g=fopen("dfs.out","w");
int n,m,x,y, viz[100001];
struct nod
{
    int info;
    nod *urm;
};
nod *a[100005];

void ADD(nod *&prim, int x)
{
    nod *q=new nod;
    q->info=x;
    q->urm=prim;
    prim=q;
}
void citire()
{  int c1, c2;
    fscanf(f,"%d %d",&n,&m);

    for(int i=1;i<=m;i++)
    {
       fscanf(f,"%d %d", &c1, &c2);
      ADD(a[c1],c2);
      ADD(a[c2],c1);
    }

}
void DFS(int x)
{
    viz[x]=1;
    for(nod *p=a[x];p!=0;p=p->urm)
      if(viz[p->info]==0) DFS(p->info);
}
int parcurgere()
{   int nrcomp=0;
    for(int i=1;i<=n;i++)
   if(viz[i]==0)
    {
        nrcomp++;
        DFS(i);
    }
    return nrcomp;
}
int main()
{
    citire();
    int s=parcurgere();

    fprintf(g,"%d",s);

    return 0;
}