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

vector<vector<int> > adjl;
vector<bool> mark;

void dfs(int i)
{
	mark[i] = true;
	for (vector<int>::iterator it = adjl[i].begin(); it != adjl[i].end(); ++it)
		if (!mark[*it]) dfs(*it);
}

int main() {
	ifstream fin("dfs.in");
	ofstream fout("dfs.out");
	int n, m;
	fin >> n >> m;
	adjl.resize(n+1);
	mark.resize(n+1);
	int u, v;
	for (; m > 0; --m) {
		fin >> u >> v;
		adjl[u].push_back(v);
		adjl[v].push_back(u);
	}

	int ans = 0;
	for (int i = 1; i <= n; ++i) {
		if (!mark[i]) {
			++ans;
			dfs(i);
		}
	}
	fout << ans;
	return 0;
}