#include <fstream>
#include <vector>
#include <queue>
#include <bitset>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int>v[100001];
bitset<100001>viz;
queue<int>q;
int i, j, k;
int n, m,start;
void apel(int st) 
{
	viz[st] = 1;
	for (vector<int>::iterator it = v[st].begin(); it < v[st].end(); it++)
	{
		if (!viz[*it]) {
			viz[*it] = 1;
			apel(*it);
		}
	}
}
int main()
{
	f >> n >> m ;
	for (int y = 1; y <= m; y++) 
	{
		f >> i >> j;
		v[i].push_back(j);
		v[j].push_back(i);
	}

	int cnt = 0;
	for (int i = 1; i <= n; i++) {
		if (!viz[i]) {
			cnt++;
			apel(i);
		}
	}
	g <<  cnt;


}