#include<fstream>
#include<vector>
using namespace std;
#define NMAX 100010

int n,m;
vector <int> g[NMAX];
bool viz[NMAX];
int nrCC;

void read()
{
	int i,x,y;

	ifstream fin("dfs.in");

	fin>>n>>m;
	for (i=1; i<=m; ++i)
	{
		fin>>x>>y;
		g[x].push_back(y);
		g[y].push_back(x);
	}

	fin.close();
}

void dfs(int nod)
{
	int i;

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

void write()
{
	ofstream fout("dfs.out");

	fout<<nrCC<<'\n';

	fout.close();
}

int main()
{
	int i;

	read();

	for (i=1; i<=n; ++i)
		if (viz[i] == 0)
		{
			nrCC++;
			dfs(i);
		}

	write();

	return 0;
}