#include <fstream>
#include <vector>

std::vector<int> muchii[100001];
bool viz[100001];

void dfs(int x) {
	viz[x] = true;
	for (const auto& v : muchii[x]) {
		if (viz[v] == false) {
			dfs(v);
		}
	}
}

int main() {
	std::ifstream fin("dfs.in");
	std::ofstream fout("dfs.out");
	int n, m, comp;

	fin >> n >> m;
	for (int i = 0; i < m; i++) {
		int a, b;
		fin >> a >> b;
		muchii[a].push_back(b);
		muchii[b].push_back(a);
	}

	comp = 0;
	for (int i = 1; i <= n; i++) {
		if (viz[i] == false) {
			dfs(i);
			comp++;
		}
	}

	fout << comp;

	return 0;
}