#include <fstream>
#include <iostream>
#include <vector>
#include <cstring>

using namespace std;

#define Nmax 100001
vector<int> vec[Nmax];
//vector<int>::iterator it;
ifstream in("dfs.in");
ofstream out("dfs.out");

void dfs(bool vazut[Nmax],int nod)
{
  vazut[nod] = true;
  if(!vec[nod].empty())
  {
    for(auto it = vec[nod].begin(); it != vec[nod].end(); it++)
    {
      if( vazut[*it] == false)
        dfs(vazut,*it);
    }
  }
}
int main()
{
  int noduri , muchii;
  in >> noduri >> muchii;
  int x ,y;
  int componente = 0;
  bool vazut[Nmax];
  for(int i = 1; i <= noduri;i++)
    vazut[i] = false;
  for(int i = 1 ;i <= muchii; i++)
  {
    in >> x >> y;
    vec[x].push_back(y);
    vec[y].push_back(x);
  }
  for(int i = 1;i <= noduri;i++)
  {
    if(vazut[i] == false)
    {
      componente++;
      dfs(vazut,i);
    }
  }
  out << componente;
  return 0;
}