//#include <gtest/gtest.h>

#include <iostream>
#include <vector>
#include <algorithm>

using std::vector;
using std::pair;

void explore(vector<vector<int>> &adj, vector<int> &visited, int v) {
	visited.push_back(v);

	for (size_t i = 0; i < adj[v].size(); i++) {
		if (std::find(visited.begin(), visited.end(), adj[v][i])
				== visited.end())
			explore(adj, visited, adj[v][i]);
	}
}

int number_of_components(vector<vector<int> > &adj) {

	vector<int> visited;
	int cc = 0;
	for (size_t v = 0; v < adj.size(); v++) {
		if (std::find(visited.begin(), visited.end(), v) == visited.end()) {
			explore(adj, visited, v);
			cc++;
		}
	}
	return cc;
}

//TEST(ConnectedComponents, cc1) {
//	vector<vector<int>> adj = { { 1 }, {0, 2 }, { 1 }, { } };
//	ASSERT_EQ(number_of_components(adj), 2);
//}

int main() {
  size_t n, m;
  std::cin >> n >> m;
  vector<vector<int> > adj(n, vector<int>());
  for (size_t i = 0; i < m; i++) {
    int x, y;
    std::cin >> x >> y;
    adj[x - 1].push_back(y - 1);
    adj[y - 1].push_back(x - 1);
  }
  std::cout << number_of_components(adj);
}