#include <iostream>
 #include <fstream>
#define N 100001
 using namespace std;
 ifstream fin("dfs.in");
 ofstream fout("dfs.out");

struct nod
{
  int info;
  nod* urm;
};

nod* vec[N];
int viz[N];// viz[i]==0

void adauga(int x, int y)
{
  nod* aux = new nod;
  aux->info = y;
  aux->urm = vec[x];
  vec[x] = aux;
}

void  dfs(int x){
 viz[x] = 1;
 // toti vecinii lui x
 // lista incepe cu vec[x]
 nod * p = vec[x];
 while(p != NULL) {
   if(viz[p -> info] == 0)
   {
     dfs(p -> info);
   }
   p=p->urm;
 }
}

int main()
{
   int n,m;
   fin>>n>>m;
   for(int i=1; i<=m; i++){
     int x,y;
     fin>>x>>y;
     adauga(x,y);
     adauga(y,x);
   }
  int cnt=0;
  for(int i=1; i<=n; i++)
   if(viz[i]==0){
     cnt++;
     dfs(i);
   }
   fout<<cnt;
	return 0;
}