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

using namespace std;

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

int  n, m, ii, jj, sol;
vector <int> v[100005];
bool a[100005];

void dfs(int nod){
      a[nod]=1;
      for(int i=0; i<v[nod].size(); i++)
            if(a[v[nod][i]] == 0)
                  dfs(v[nod][i]);
}

int main(){
      fin>>n>>m;
      for(int i=1; i<=m; i++){
            fin>>ii>>jj;
            v[ii].push_back(jj);
            v[jj].push_back(ii);
      }

      for(int i=1; i<=n; i++)
            if(a[i] == 0){
                  dfs(i);
                  sol++;
            }

      fout<<sol;
      return 0;
}