#include <bits/stdc++.h>

#define NMAX 16005

using namespace std;

ifstream fin ("asmax.in");
ofstream fout ("asmax.out");

int C[NMAX];
vector < int > G[NMAX];
bitset < NMAX > T;


void Dfs(int nod,int &S,int s,int &st){
    if(T[nod] == 1)
        return;
    T[nod] = 1;
    for(int i = 0; i < G[nod].size(); i++){
        st += C[G[nod][i]];

        if(st > s)
            s = st;
        Dfs(G[nod][i],S,s,st);
        if(st > s)
            s = st;
        if(S < s)
            S = s;
    }
}

int main()
{
    ios :: sync_with_stdio(false);
    fin.tie(NULL);

    int n,S,s,st,x,y;

    fin >> n;

    for(int i = 1; i <= n; i ++)
        fin >> C[i];
    S = C[1];

    for(int i = 1; i < n; i++){
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= n; j++)
            T[j] = 0;
        s = st = C[i];
        Dfs(i,S,s,st);
    }

   fout << S;
    return 0;
}