#include<iostream>
#include<fstream>

using namespace::std;
int  m, n, k, viz[100005];

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


typedef struct nod
{
	int info;
	nod *next;
} *pN;
pN a[100005];


void add(pN &dest, int val)
{
	pN q;
	q = new nod;
	q->info = val;
	q->next = dest;
	dest = q;
}


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

	f >> n >> m;
	for (i = 1; i <= m; i++)
	{
		f >> x >> y;
		add(a[x], y);
		add(a[y], x);
	}

}

void Dfs(int nod)
{
	pN p;
	viz[nod] = 1;
	for (p = a[nod];p!=NULL;p=p->next)
	if (!viz[p->info])
		Dfs(p->info);
}



int main()
{
	int i;
	
	citire();
	
	for (i = 1; i <= n;i++)
	if (viz[i] == 0)
	{
		k++;
		Dfs(i);
	}

	g<< k;
}