#include <iostream>
#include <cstdio>
#include <cstring>
#include <iomanip>
using namespace std;
int n;
int mon[100001],ans[100001]={0};
int a[1001][1001]={0},num[100001]={0};
int main()
{
	freopen("profitz.in","r",stdin);
	freopen("profitz.out","w",stdout);
	int n;
	int i,j,k;
	int sum=0;
	cin>>n;
	for(i=1;i<=n;i++)
		cin>>mon[i];
	for(i=1;i<=n-1;i++)
	{
		int c,b;
		cin>>c>>b;
		num[c]++;
		num[b]++;
		a[c][b]++;
		a[b][c]++;
	}
	for(i=1;i<=n;i++)
	{
		if(num[i]==1)
		{
			sum+=mon[i];
		}
	}
	cout<<sum;
	return 0;
}