#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <algorithm>
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <deque>
#include <map>
#include <set>
#include <bitset>
#include <complex>
#include <string>
#define REP(i,j) for(int i=1;i<=j;++i)
#define REPI(i,j,k) for(int i=j;i<=k;++i)
#define REPD(i,j) for(int i=j;0<i;--i)
#define CLR(s) memset(s,0,sizeof s)
#define SET(s,v) memset(s,v,sizeof s)
#define mp make_pair
#define pb push_back
#define x first
#define y second
using namespace std;
string FILE_NAME = "meat";
typedef long long LL;
typedef double DB;
const int INF = 0x3f3f3f3f;

const int maxn = 500000 + 500;

int fa[maxn],son[maxn],n;
DB A[maxn],F[maxn];
struct Edge
{
	int head[maxn],next[maxn],to[maxn];
	int edge;
	void init()
	{
		edge=0;
		SET(head,-1);
	}
	void addedge(int a,int b)
	{
		next[edge]=head[a];
		to[edge]=b;
		head[a]=edge++;
	}
}E;

int cnt;

int dcmp(DB d)
{
	if(fabs(d)<1e-8)
		return 0;
	return d<0?-1:1;
}

DB add[maxn];

void dfs(int t)
{
	if(son[t]==0) return ;
	for(int i=E.head[t];i!=-1;i=E.next[i])
	{
		F[E.to[i]]=F[t]+add[t];
		dfs(E.to[i]);
	}
}

bool cmp(DB a,DB b)
{
	return dcmp(a-b)<0;
}

int main()
{

	scanf("%d",&n);
	E.init();
	for(int i=1;i<=n;++i)
	{
		scanf("%lf",&A[i]);
	}
	for(int i=1;i<n;++i)
	{
		int a,b;
		scanf("%d%d",&a,&b);
		fa[b]=a;
		++son[a];
		E.addedge(a,b);
	}

	for(int i=1;i<=n;++i)
	{
		add[i]=log(son[i]);
	}

	F[1]=0;
	dfs(1);
	for(int i=1;i<=n;++i)
	{
		F[i]+=log(A[i]);
	}

	sort(F+1,F+n+1,cmp);
	int ans=0;
	for(int i=1;i<=n;++i)
	{
		int cnt=1;
		while(dcmp(F[i]-F[i+1])==0 && i+1<=n)
		{
			++cnt;
			++i;
		}
		if(cnt>ans)
			ans=cnt;
	}
	printf("%d\n",n-ans);
	return 0;
}