/*
Parcurgerea in adancime intr-un graf.
*/

#include <iostream>
#include <vector>
#include <stdio.h>
#include <stdbool.h>

#define MAXN	100050

using namespace std;

int nr_noduri, nr_muchii, nr_comp_conexe;
bool vizitat[MAXN];
vector<int> noduri[MAXN];

void dfs (int u) {
	int i;
	vizitat[u] = 1;
	for (i = 0; i < noduri[u].size(); i++) 
		if (!vizitat[noduri[u][i]]) 
			dfs(noduri[u][i]);
}

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

	int i, x, y;
	scanf("%d %d", &nr_noduri, &nr_muchii);
	for (i = 0; i < nr_muchii; i++) {
		scanf("%d %d", &x, &y);
		noduri[x].push_back(y);
		noduri[y].push_back(x);
	}

	nr_comp_conexe = 0;
	for (i = 1; i <= nr_noduri; i++) {
		if (!vizitat[i]) {
			nr_comp_conexe++;
			dfs(i);
		}
	}

	printf("%d\n", nr_comp_conexe);

	return 0;
}