#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;
  for (int i = 0; i < v[node].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;
}