#include <fstream>
#include <queue>
#include <vector>
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int viz[100005];
vector<int>vecini[100005];
void dfs(int nod, int cnt)
{
	int i;
	viz[nod] = cnt;
	for (i = 0; i < vecini[nod].size(); i++)
		if (viz[vecini[nod][i]] == 0)
			dfs(vecini[nod][i], cnt);
}
int main()
{
	int n, m, s, i;
	fin >> n >> m;
	int x, y;
	for (i = 1; i <= m; i++)
	{
		fin >> x >> y;
		vecini[x].push_back(y);
		vecini[y].push_back(x);
	}
	int cnt = 0;
	for (i = 1; i <= n; i++)
	{
		if (viz[i] == 0)
		{
			cnt++;
			dfs(i, cnt);
		}
	}
	fout << cnt;


}