#include <iostream>
#include <vector>

void dfs(int node, std::vector<bool> &vis, std::vector<std::vector<int>> &adj) {
	vis[node] = true;
	for (int neigh : adj[node]) {
		if (!vis[neigh]) {
			dfs(neigh, vis, adj);
		}
	}
}

int main(void) {
	std::cin.tie(0);

#ifndef LOCAL
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);
#endif

	int n, m;

	std::cin >> n >> m;

	std::vector<std::vector<int>> adj(n + 1, std::vector<int>());

	for (int i = 0; i < m; ++i) {
		int x, y;

		std::cin >> x >> y;

		adj[x].push_back(y);
		adj[y].push_back(x);
	}

	std::vector<bool> vis(n + 1, false);

	int ans = 0;

	for (int i = 1; i <= n; ++i) {
		if (!vis[i]) {
			dfs(i, vis, adj);
			ans++;
		}
	}

	std::cout << ans << '\n';

	return 0;
}