#include <fstream>
#include <iostream>
#include <vector>
typedef long long ll;

using namespace std;

bool dfs(vector<vector<ll>> &matrix, vector<bool> &visited, int current) {
  visited[current] = true;
  for (ll &el : matrix[current]) {
    if (!visited[el]) {
      dfs(matrix, visited, el);
    }
  }
}

int main() {
  ifstream cin("dfs.in");
  ofstream cout("dfs.out");
  ll n, m;

  cin >> n >> m;
  vector<vector<ll>> matrix(n + 1, vector<ll>());
  vector<bool> visited(n + 1, false);

  for (ll i = 0; i < m; ++i) {
    ll a, b;
    cin >> a >> b;
    matrix[a].push_back(b);
    matrix[b].push_back(a);
  }

  int solve = 0;
  for (ll i = 1; i <= n; ++i) {
    if (visited[i] == false) {
      solve++;
      dfs(matrix, visited, i);
    }
  }

  cout << solve << endl;
  return 0;
}