#include<fstream>
#include<vector>
using namespace std;
int viz[100001],i,n,m,con=0;
ifstream f("dfs.in");
ofstream g("dfs.out");

vector <int>A[100001];

void Citire()
{
     int i,x,y;
f>>n>>m;
   for(i=1;i<=m;i++)
   {
   f>>x>>y;
   A[x].push_back(y);
   A[y].push_back(x);                
   }
f.close();
}

   void df(int nod)
   {
   viz[nod]=1;
      int nr_vecini;
      nr_vecini=A[nod].size();
         for(int i=0;i<nr_vecini;i++)
         if(viz[A[nod][i]]==0)
         df(A[nod][i]);
   }
      
      int main()
      {
      Citire();
      
      for(i=1;i<=n;i++)
      if(viz[i]==0)    
      {df(i);con++;}
      g<<con;
      
      
        return 0;
   
}