#include <bits/stdc++.h>

using namespace std;

int main() {
	#ifdef BLAT
		freopen("input", "r", stdin);
	#else
		freopen("dfs.in", "r", stdin);
		freopen("dfs.out", "w", stdout);
	#endif

	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);

	int n, m;
	cin >> n >> m;

	vector< vector< int > > gr(n + 1);
	vector< bool > viz(n + 1);
	int ans = 0;

	for(int i = 0; i < m; ++i) {
		int a, b;
		cin >> a >> b;
		gr[a].emplace_back(b);
		gr[b].emplace_back(a);
	}

	function< void(int) > dfs = [&](int node) {
		viz[node] = true;
		for(auto &x : gr[node]) if(!viz[x]) dfs(x);
		return;
	};
		
	for(int i = 1; i <= n; ++i) {
		if(!viz[i]) {
			++ans;
			dfs(i);
		}
	}

	cout << ans << '\n';
	return 0;
}