#include <fstream>
#include <vector>
#include <bitset>
using namespace std;
const int N = 1e5;
ifstream cin("dfs.in");
ofstream cout("dfs.out");
vector <int> a[N + 1];
bitset <N + 1> viz;

int n, cnt;


void citire()
{
	int x, y, k;
	cin >> n >> k;
	for (int i = 0; i < k; i++)
	{
		cin >> x >> y;
		a[x].push_back(y);
		a[y].push_back(x);
	}

}

void DFS(int x)
{
	viz[x] = 1;
	for (int i:a[x])
	{
		if (!viz[i])
		{
			DFS(i);
		}
	}
}
int main()
{
	citire();
	for (int i = 1; i <= n; i++)
	{
		if (!viz[i])
		{
			DFS(i);
			cnt++;
		}
	}
	cout << cnt;
}