#include <iostream>   
#include <cstdio>   
#include <cstdlib>   
#include <cmath>   
#include <cstring>   
#include <string>   
#include <algorithm>   
#include <iomanip>   
using namespace std;  
struct fun
{
	int x;
	int y;
}f[200000]={0};
int b,c,d,l,m,n[150000],r[150000],k[150000],s=0;
int Compare(const void *elem1,const void *elem2)
{
	struct fun *elem3 = (struct fun *)elem1;
	struct fun *elem4 = (struct fun *)elem2;
	if(elem3->x != elem4->x) return elem3->x - elem4->x;
		else return elem3->y - elem4->y;
}
int main(void)   
{   
    freopen ("profitz.in","r",stdin);   
    freopen ("profitz.out","w",stdout);   
	scanf("%d",&b);
	for (c=1;c<=b;c++) scanf("%d",&k[c]);
	for (c=0;c<b-1;c++)
	{
		scanf("%d%d",&l,&m);
		f[c*2].x=l;
		f[c*2].y=m;
		f[c*2+1].x=m;
		f[c*2+1].y=l;
		r[l]++;
		r[m]++;
	}
	qsort(f,2*b-2,sizeof(fun),Compare);
	d=1;
	n[0]=0;
	for (c=1;c<2*b-1;c++)
		if (f[c].x!=f[c-1].x) 
		{
			n[d]=c;
			d++;
		}
	for (c=1;c<=b;c++)
		if (r[c]==1)
		{
			s+=k[c];
			if (r[f[n[c-1]].y]!=0)
			{
				r[f[n[c-1]].y]=0;
				for (d=n[f[n[c-1]].y-1];d<n[f[n[c-1]].y];d++)
					if (r[f[d].y]>1) r[f[d].y]--;
			}
			r[c]=0;
		}
	cout<<s;
    fclose(stdin);   
    fclose(stdout);   
    return 0;   
}