[HAOI2006] 聪明的猴子

// q.c

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
#include<cmath>
using namespace std;
const int M=1000+10;
struct Edge {
	int u,v; double w;
	Edge():u(0),v(0),w(0) {}
	bool operator < (const Edge &A) const {
		return w<A.w;
	}
}ed[M*M>>1];
int m,n,cnt,w[M],x[M],y[M],fa[M],ans;
void add_edge(int a,int b,double c) {
	ed[++cnt].u=a,ed[cnt].v=b,ed[cnt].w=c;
}
double dis(int a,int b) {
	return sqrt((x[a]-x[b])*(x[a]-x[b])*1.0+(y[a]-y[b])*(y[a]-y[b]));
}
int find(int a) {
	return fa[a]==a?a:fa[a]=find(fa[a]);
}
double kruscal() {
	sort(ed+1,ed+cnt+1);
	int k=1; double maxx=0;
	for(int i=1;i<=cnt;i++) {
		Edge p=ed[i];
		int fu=find(p.u);
		int fv=find(p.v);
		if(fu==fv) continue;
		fa[fu]=fv; ++k;
		if(k==n) { // ~~~if(k==n-1)~~~
			maxx=p.w;
			break;
		}
	}
	return maxx;
}
int main() {
	freopen("monkey.in","r",stdin);
	freopen("monkey.out","w",stdout);
	scanf("%d",&m);
	for(int i=1;i<=m;i++) scanf("%d",&w[i]);
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d%d",&x[i],&y[i]),fa[i]=i;
	for(int i=1;i<=n;i++) 
		for(int j=i+1;j<=n;j++)
			add_edge(i,j,dis(i,j));
	double maxx=kruscal();
	for(int i=1;i<=m;i++) if(w[i]>=maxx) ans++;
	printf("%d\n",ans);
	return 0;
}