#include <fstream>
#include <vector>
#include <algorithm>
#define NMAX 100001

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n,nrc;
vector <int> g[NMAX];
bool viz[NMAX]; //viz[i]=1; daca vf i a fost vizitat si 0 in caz contrar
void citire();
void dfs(int x);

int main()
{
    citire();
    for(int i=1;i<=n;i++)
        if(!viz[i])
    {
      nrc++;
      dfs(i);
    }
    fout<<nrc<<'\n';
    return 0;
}
void citire()
{
  int i,j,m,k;
  fin>>n>>m;
  for(k=0;k<m;k++)
  {
    fin>>i>>j;
    g[i].push_back(j);
    g[j].push_back(i);
  }
  /*for(i=1;i<=n;i++)
      sort(g[i].begin(), g[i].end());*/

}
void dfs(int x)
{
  int i;
  //fout<<x<<' ';
  viz[x]=1;
  //parcurg vecinii vf x
  for(i=0;i<g[x].size();i++)
    if(!viz[g[x][i]])
       dfs(g[x][i]);
}