#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;   
}