#include <iostream>
#include <fstream>
#include <vector>
#include <string.h>

#define MAX 100005
#define TRUE 1
#define FALSE 0

using namespace std;

typedef struct {
	int n;
	vector <vector <int> > V;
} Graph;

Graph G;
bool found[MAX];

void read() {
	int m;
	cin >> G.n >> m;
	
	for (int i = 0; i <= G.n; ++i) {
		vector <int> v;
		G.V.push_back(v);
	}
	
	for (int i = 0; i < m; ++i) {
		int x, y;
		cin >> x >> y;
		G.V[x].push_back(y);
		G.V[y].push_back(x);
	}
}

void dfs(int id) {
	for (unsigned int i = 0; i < G.V[id].size(); ++i) {
		if (!found[G.V[id][i]]) {
			found[G.V[id][i]] = TRUE;
			dfs(G.V[id][i]);
		}
	}
}

int main(void) {
	ios::sync_with_stdio(false);
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);
	
	read();
	
	int n = 0;
	for (int i = 1; i <= G.n; ++i) {
		if (!found[i]) {
			++n;
			dfs(i);
		}
	}
	
	cout << n;
	
	return 0;
}