#include <fstream>
#include <vector>
#define NMAX 100000

using namespace std;

int viz[NMAX + 1];
vector <int> v[NMAX + 1];

void dfs (int node){

  viz[node] = 1;
  int _size = v[node].size();
  for (int i = 0; i < _size; i++){
    if (!viz[v[node][i]])
      dfs (v[node][i]);
  }

}
int main(){
  ifstream fin ("dfs.in");
  ofstream fout ("dfs.out");

  int n, m, x, y;
  fin >> n >> m;

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

  int rez = 0;
  for (int i = 1; i <= n; i++)
    if (!viz[i]){
      rez ++;
      dfs(i);
    }

  fout << rez;
  return 0;
}