#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];
 int insula =0;

void DFS(int nod){

    unsigned int i;

   viz[nod]=1;

   for(i=0;i<muchii[nod].size();i++){
      int vecin=muchii[nod][i];

      if(viz[vecin]==0)DFS(vecin);
   }

}


void citire(){
    fin>>n>>m;

    for(int i=1;i<=m;i++){
            int x,y;
        fin>>x>>y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }

    for(int i=1;i<=n;i++){

          if(viz[i]==0){insula+=1;DFS(i);}

    }

}


int main()
{
    citire();
     fout<<insula<<endl;
    return 0;
}