#include<fstream>
#include<vector>

using namespace std;

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

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

void dfs(int nod)
{
	ok[nod]=1;
	for (vector<int>::iterator it=a[nod].begin();it!=a[nod].end();it++)
		if (!ok[*it]) dfs(*it);
}

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