#include<iostream>
#include<cmath>
#include<cstdio>
#include<cctype>
#include<ctime>
#include<queue>
#include<list>
#include<stack>
#define xlm mylove
#define lyz goodboy
#define itn int
using namespace std;
typedef long long LL;typedef unsigned long long ULL;
const int maxn=50100;
int fa[maxn],n,m,temp1,temp2;
inline int ff(int x){
	if (fa[x]==x) return fa[x];
	else return fa[x]=ff(fa[x]);
}
inline void unite(int x,int y){
	int a=ff(x);int b=ff(y);
	if (a!=b){
		fa[a]=fa[b];
	}
}
inline void init(int n){
	for (int i=1;i<=n;i++){
		fa[i]=i;
	}
}
inline int p(int n){
	int ans=0;
	for (int i=1;i<=n;i++){
		if (fa[i]==i) ans++;
	}
	return ans;
}
inline void in(){
	freopen("religion.in","r",stdin);
	freopen("religion.out","w",stdout);
	scanf("%d%d",&n,&m);init(n);
	for (int i=1;i<=m;i++){
		scanf("%d%d",&temp1,&temp2);
		unite(temp1,temp2);
	}
}
inline void out(){
	printf("%d",p(n));
}
int Main(){
	in();
	out();
	return 0;
}
int goodboy=Main();
int main(){;}