#include <fstream>
#include <vector>

using namespace std;

ifstream fi("dfs.in");
ofstream fo("dfs.out");
vector<int> vecini[100001];
int n, m, ncc, viz[100001];

void citire () {
  int i, x, y;

  fi >> n >> m;
  for (i = 1; i <= m; i++) {
    fi >> x >> y;
    vecini[x].push_back(y);
    vecini[y].push_back(x);
  }
}

void df (int nod) {
  int i;

  viz[nod] = true;
  for (i = 0; i < vecini[nod].size(); i++)
    if (!viz[vecini[nod][i]])
      df (i);
}

int main () {
  int i;

  citire();
  for (i = 1; i <= n; i++)
    if (!viz[i]) {
      ncc++;
      df(i);
    }
  fo << ncc;
  return 0;
}