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

vector <int> a[100001];
int i,n,m,x,y,nr,v[100001];

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

int main()
{
	ifstream f("dfs.in");
	ofstream g("dfs.out");
	f >> n >> m;
	for (i=1;i<=m;i++)
	{
		f >> x >> y;
		a[x].push_back(y);
		a[y].push_back(x);
	}
	for (i=1;i<=n;i++)
		if (v[i]==0)
		{
			dfs(i);
			nr++;
		}
	g << nr;
	return 0;
}