#include <fstream>
#include <vector>
#define max 100001
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> a[max];
char viz[max];
int n,m,nr;

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


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