#include<iostream>
#include<algorithm>
#include<stdlib.h>
#include<stdio.h>
#include<vector>
using namespace std;
int i,j,k,l,m,n,sum,a[1000005],x,y,f[1000005],ans,ans1;
vector<int>v[1000005];
int go(int u)
{
    f[u]=1;


    int su=0;
    int ma=0;
    for(int i=0;i<v[u].size();i++)
       if(!f[v[u][i]])
       {
           int w=go(v[u][i]);
           ma=max(ma,w);
           su+=w;
       }
    ma=max(ma,sum-su-a[u]);
    if(ans>ma)ans=ma,ans1=u;
    return su+a[u];
}
main()
{
    scanf("%d",&n);

    for(int i=0;i<n;i++)scanf("%d",&a[i]),sum+=a[i];


    for(int i=1;i<n;i++)
    {
        scanf("%d%d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    ans=int(2e9+1);
    go(0);

    cout<<ans1<<endl;
}