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

const int nmax=100001;

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

int n, m, x, y;
vector<int> ad[nmax];
bitset<nmax> viz;


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

int main()
{
	fin >> n >> m;
	for (int i = 1; i <= m; i++)
	{
		fin >> x >> y;
		ad[x].push_back(y);
		ad[y].push_back(x);
	}
	int sol = 0;
	for (int i = 1; i <= n; i++)
	{
		if (!viz[i])
		{
			sol++;
			dfs(i);
		}
	}
	fout << sol;
}