#include <fstream>
#include <vector>

using namespace std;

void dfs(vector<vector<int>> &graph, vector<bool> &visited, int node) {
  visited[node] = true;

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

int main() {
  int n, m;
  ifstream fin("dfs.in");
  ofstream fout("dfs.out");
  fin >> n >> m;
  vector<vector<int>> graph(n + 1, vector<int>());
  for (int i = 1; i <= m; i++) {
    int x, y;
    fin >> x >> y;
    graph[x].push_back(y);
    graph[y].push_back(x);
  }
  int countt = 0;
  vector<bool> visited(n + 1);
  for (int i = 1; i <= n; i++) {
    if (!visited[i]) {
      countt++;
      dfs(graph, visited, i);
    }
  }
  fout << countt << "\n";

  return 0;
}