#include<fstream.h>
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define max 100007
long n,m,cc;
char viz[max];
struct nod{long info;
           nod *urm;
           }*g[max];

void adauga(long x,long y)
{nod *c=new nod;
 c->info=y;
 c->urm=g[x];
 g[x]=c;
 }

void dfs(int k)
{viz[k]=1;
 nod *p;
 for(p=g[k];p!=NULL;p=p->urm)
     if(!viz[p->info])dfs(p->info);

}


int main()
{
fin>>n>>m;
long i,a,b,cc=0;
for(i=1;i<=m;i++)
     {fin>>a>>b;
     adauga(a,b);
     adauga(b,a);
     }
for(i=1;i<=n;i++)
   if(!viz[i]){cc++;dfs(i);}

      fout<<cc;

  fin.close();
  fout.close();
  return 0;
  }