#include<vector>
#include<fstream>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int N = 100001;

static int viz[N];
vector <int> g[N];

void dfs(int x)
{
	viz[x] = 1;
	for (int i = 0; i < g[x].size(); i++)
	{
		if(!viz[g[x][i]]) dfs(g[x][i]);
	}
}

int main()
{

	int n, m;
	fin >> n >> m;
	for (int i = 1; i <= m; i++)
	{
		int x, y;
		fin >> x >> y;
		g[x].push_back(y);
		g[y].push_back(x);
	}
	int nr = 0;
	for (int i = 1; i <= n; i++)
	{
		if (!viz[i])
		{
			dfs(i);
			nr++;
		}

	}
	fout << nr;



}