#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>


typedef std::vector<int>::iterator iter;


std::ifstream f("dfs.in");
std::ofstream g("dfs.out");

const int MAXN = 100005;
int n, m;
std::vector<int> G[MAXN];
std::bitset<MAXN> viz;


void dfs(int nd) {
	viz[nd] = true;
	for (iter it = G[nd].begin(); it != G[nd].end(); it++) {
		if (!viz[*it]) {
			dfs(*it);
		}
	}
}


int main()
{
	f >> n >> m;
	for (int i = 1, x, y; i <= m; i++) {
		f >> x >> y;

		G[x].push_back(y);
		G[y].push_back(x);
	}


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

	g << sol << std::endl;


	return 0;
}