#include <iostream>
#include <vector>
using namespace std;

#define MAXN 100005

int N, M;
vector<int> G[MAXN];
char viz[MAXN];

void ReadData() {
	cin >> N >> M;
	for (int i = 0; i < M; ++i) {
		int a, b;
		cin >> a >> b;

		G[a].push_back(b);
		G[b].push_back(a);
	}
}

void DF(int nod) {
	viz[nod] = 1;
	for (vector<int>::iterator it = G[nod].begin(); it != G[nod].end(); ++it)
		if (!viz[*it])
			DF(*it);
}

void Solve() {
	int componente = 0;
	for (int i = 1; i <= N; ++i)
		if (!viz[i]) {
			++componente;
			DF(i);
		}
	cout << componente << '\n';
}

int main() {
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);

	ReadData();
	Solve();
}