#include <stdio.h>
#include <vector>
using namespace std;

vector <int> g[100010];
int v[100010];
int n,m,rez;
int i,a,b;
int cc[100010];

void dfs(int nod)
{
	int ii;
	if(v[nod]){
		return ;
	}
	cc[nod]=rez;
	v[nod]=1;
	for(ii=0;ii<g[nod].size();ii++){
		dfs(g[nod][ii]);
	}
}

int main()
{
 	freopen("dfs.in","r",stdin);
 	freopen("dfs.out","w",stdout);
 	scanf("%d%d",&n,&m);
 	for(i=1;i<=m;i++){
		scanf("%d%d",&a,&b);
		g[a].push_back(b);
		g[b].push_back(a);
	}
	for(i=1;i<=n;i++){
		if(!v[i]){
			rez++;
			dfs(i);
		}
	}
	printf("%d\n",rez);
	/*for(i=1;i<=n;i++){
		printf("%d %d\n",i,cc[i]);
}	*/		
	return 0;
}