#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <fstream>

using namespace std;

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

vector<int> v[100001];
int n,m,x,y,parcurs[100001],nr;

void dfs(int t)
{
 if (parcurs[t]==0)
 {
   parcurs[t]=1;
   for (auto i:v[t])
    dfs(i);
 }
}

int main()
{
  fin>>n>>m;
  for (int i=1;i<=m;i++)
  {
    fin>>x>>y;
    v[x].push_back(y);
    v[y].push_back(x);
  }
  for (int i=1;i<=n;i++)
    if (parcurs[i]==0)
    {
      nr++;
      dfs(i);
    }
  fout<<nr;
}