#include<stdio.h>
const int maxn = 110;
int father[maxn];
bool isRoot[maxn];
void init(int n)
{
    
    
	for(int i = 1; i <= n; i++)
	{
    
    
		father[i] = i;
		isRoot[i] = false;
	}
}
int findFather(int x)
{
    
    
	while(x != father[x])
	{
    
    
		x = father[x];
	}
	return x;
}

void Union(int a, int b)
{
    
    
	int faA = findFather(a);
	int faB = findFather(b);
	if(faA != faB)
	{
    
    
		father[faA] = faB;
	}
}

int main()
{
    
    
   int n, m, a, b;
   scanf("%d%d", &n, &m);
   init(n);
   for(int i = 0; i < m; i++)
   {
    
    
   	  scanf("%d%d", &a, &b);
   	  Union(a, b);
   }
   for(int i = 1; i <= n; i++)
   {
    
    
   	  isRoot[findFather(i)] = true;
   }
   int ans = 0;
   for(int i = 1; i <= n; i++)
   {
    
    
   	   ans += isRoot[i];
   }
   printf("%d\n", ans);
   return 0;
}