#include <bits/stdc++.h>

using namespace std;

ifstream in("dfs.in");
ofstream out("dfs.out");

const int N = 1e5;
vector<vector<int>> adj(N);
bool visited[N];

void dfs(int x) {
	visited[x] = true;
	for(auto y : adj[x]) {
	 	if(!visited[y]) dfs(y);
	}
}

int main() {
	int n, m;
	in >> n >> m;
	vector<array<int, 2>> edges(m);
	for(int i = 0; i < m; i++) {
		in >> edges[i][0] >> edges[i][1];
		edges[i][0]--, edges[i][1]--;
		adj[edges[i][0]].push_back(edges[i][1]);
		adj[edges[i][1]].push_back(edges[i][0]);
	}
	in.close();
	int ans = 0;
	for(int i = 0; i < n; i++) {
	 	if(!visited[i]) {
	 	 	ans++;
	 	 	dfs(i);
	 	}
	}
	out << ans << '\n';
	out.close();
	return 0;
}