#include <stdio.h>
	
 
	
int n, m, viz[100005], cnt;
	
 
	
typedef struct nod
	
{
	
	int x;
	
	nod *a;
	
} *pNod;
	
pNod v[100005];
	
 
	
void add(pNod &dest, int val)
	
{
	
	pNod p;
	
	p = new nod;
	
	p -> x = val;
	
	p -> a = dest;
	
	dest = p;
	
}
	
 
	
void citire()
	
{
	
	freopen("dfs.in","r",stdin);
	
	freopen("dfs.out","w",stdout);
	
	scanf("%d %d",&n,&m);
	
	int i, x, y;
	
 
	
	for (i = 1; i <= m; i++)
	
	{
	
		scanf("%d %d",&x,&y);
	
		add(v[x], y);
	
		add(v[y], x);
	
	}
	
}
	
 
	
void DFS(int nod)
	
{
	
	pNod p;
	
	viz[nod] = 1;
	
	for (p = v[nod]; p != NULL; p = p -> a) if (!viz[p -> x]) DFS(p -> x);
	
}	
	
 
	
int main()
	
{
	
	citire();
	
	int i;
	
	for (i = 1; i <= n; i++) if (!viz[i]) { cnt++; DFS(i);}
	
	printf("%d\n",cnt);
	
	return 0;
	
}