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

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

const int N=200005;
vector <int> a[N];
bool use[N];

void dfs(int x)
{
	use[x]=true;
	for(vector<int>:: iterator i=a[x].begin(); i!=a[x].end();i++)
		if(!use[*i])
			dfs(*i);
}

int main()
{
	int n,m,nr=0,x,y;
	in>>n>>m;
	while(m--)
	{
		in>>x>>y;
		a[x].push_back(y);
		a[y].push_back(x);
	}
	
	for(int i=1;i<=n;i++)
		if(!use[i])
		{
			dfs(i);
			nr++;
		}
	out<<nr;
}