#include<fstream>
#include<vector>

using namespace std;

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

const int NMAX = 100001;
vector<int> A[NMAX];
int vizite[NMAX];

void dfs(int nod) {
	vizite[nod] = 1;
	for (int i = 0; i < A[nod].size(); ++i)
		if (vizite[A[nod][i]] == 0) {
			dfs(A[nod][i]);
		}
}

int main() {
	int N, M;
	fin >> N >> M;
	for (int i = 0; i < M; ++i) {
		int x, y;
		fin >> x >> y;
		A[x].push_back(y);
		A[y].push_back(x);
	}
	int total = 0;
	for (int i = 1; i <= N; ++i)
		if (vizite[i] == 0) {
			dfs(i);
			total++;
		}
	fout << total;
	fin.close();
	fout.close();
	return 0;
}