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

using namespace std;

const int MAXN = 100001;

vector<int> adj[MAXN];
vector<bool> visited;
int N, M;

void dfs(int node) {
  visited[node] = true;

  for (int neighbor : adj[node]) {
    if (!visited[neighbor]) {
      dfs(neighbor);
    }
  }
}

int countConnectedComponents() {
  visited.assign(N + 1, false);
  int components = 0;

  for (int i = 1; i <= N; i++) {
    if (!visited[i]) {
      dfs(i);
      components++;
    }
  }

  return components;
}

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

  fin >> N >> M;

  for (int i = 0; i < M; i++) {
    int x, y;
    fin >> x >> y;
    adj[x].push_back(y);
    adj[y].push_back(x);
  }

  int result = countConnectedComponents();
  fout << result << "\n";

  fin.close();
  fout.close();
  return 0;
}