#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

void dfs(int node, vector<vector<int>>& edges, vector<bool>& viz) {
	viz[node] = true;
	for (auto nxt : edges[node]) {
		if (!viz[nxt]) {
			dfs(nxt, edges, viz);
		}
	}
}

int main() {
	ifstream cin("dfs.in");
	ofstream cout("dfs.out");

	/*
	 liste de adiacenta:
	 	1: 2, 3, 7
	 	2: 1, 6
	 	3: 6, 1, 4
	 	4: 3, 5
	 	5: 4, 8, 9
	 	...
	*/

	int n, m; cin >> n >> m;
	vector<vector<int>> edges(n);
	for (int i = 0; i < m; i++) {
		int a, b; cin >> a >> b;
		a--; b--;
		edges[a].push_back(b);
		edges[b].push_back(a);
	}

	vector<bool> viz(n);
	int cnt = 0;
	for (int i = 0; i < n; i++) {
		if (!viz[i]) {
			cnt++;
			dfs(i, edges, viz);
		}
	}

	return 0;
}