#include <bits/stdc++.h>
#include <vector>
#define NMAX 100004
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector<int> a[NMAX];
vector<int> conex[NMAX];
bool viz[NMAX];
int nrsol,lg[NMAX];
int n,m,start,cnt;
void dfs(int x);
void citire();
int main()
{
   citire();
   for(int i=1;i<=n;i++)
   {
        if(viz[i]==0)
        {
            nrsol++;
            dfs(i);
        }
   }
   fout<<nrsol<<'\n';
    return 0;
}
void citire()
{
 fin>>n>>m;
 int x,y;
 for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
     a[x].push_back(y);
     ///adaug pe y in lista de adiacenta a lui x
     a[y].push_back(x);
     ///adaug pe x in lista de adiacenta a lui y
    }
}
void dfs(int x)
{
  conex[nrsol].push_back(x);
  viz[x]=1;
  for(int i=0;i<a[x].size();i++)
  {
     if(!viz[a[x][i]])
     {
        dfs(a[x][i]);
     }
  }
}