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

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

const int NLIM=100005;

vector <int> muchii[NLIM];

int n,m,viz[NLIM];


void DFS(int nod){

    unsigned int i;

   viz[nod]=1;

   for(i=1;i<=muchii[nod].size();i++){
      int vecin=muchii[nod][i];
      if(!viz[vecin])DFS(vecin);
   }

}


void citire(){
    fin>>n>>m;int x,y,i;
    for(i=1;i<=m;i++){
        fin>>x>>y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    int insula =0;
    for(i=1;i<=n;i++){
          if(!viz[i]){DFS(i);insula++;}
    }
   fout<<insula;
}


int main()
{
    citire();

    return 0;
}