#include <cstdio>
#define nmax 16002
#include <queue>
#include <algorithm>

using namespace std;

int N,t[nmax],d[nmax],s[nmax],rez = 0;
queue <int> Q;
queue <pair<int,int> > P;

int main(){
  
  freopen("asmax.in","r",stdin);
  freopen("asmax.out","w",stdout);
  
  scanf("%d ",&N);
  int i,j,k;
  for(i = 1;i <= N;++i){
    scanf("%d ",&s[i]);
    rez = min(rez,s[i]);
  }
  for(i = 1;i < N;++i){
    scanf("%d %d ",&j,&k);
    P.push(make_pair(j,k));
    d[j]++;d[k]++;
  }

  while(!P.empty()){
    j = P.front().first;
    k = P.front().second;
    P.pop();
    if(d[j] > d[k])t[k] = j;
    else           t[j] = k;
  }

  //for(i = 1;i <= N;i++)printf("%d %d\n",t[i],d[i]);
  
  for(i = 1;i <= N;++i){
    if(d[i] == 1){Q.push(i);d[i] = 0;}
    if(t[i] == 0)d[i]++;
  }

  s[0] = 0;
  while(!Q.empty()){
    i = Q.front();
    Q.pop();
    
      s[t[i]] = max(s[t[i]],s[t[i]] + s[i]);
      d[t[i]]--;
      if(d[t[i]] == 1)Q.push(t[i]);
   
    rez = max(rez,s[i]);
  }

  printf("%d\n",rez);

  return 0;
}