#include<bits/stdc++.h>
using namespace std;
ifstream fin("asmax.in");
ofstream fout("asmax.out");
const int Nmax = 16005;
vector <int> L[Nmax];
int maxm = INT_MIN, dp[Nmax], viz[Nmax], c[Nmax];
void dfs(int nod)
{
    dp[nod] = c[nod]; //initializare
    viz[nod] = 1;
    for(int i = 0; i<L[nod].size();i++)
    {
        int vec = L[nod][i];
        if(!viz[vec]) // ma asigur ca dupa ce am ajuns la o frunza nu ma mai intorc(nu ma refer cand termin efectiv toata recursia)
        {
            dfs(vec);

            dp[nod] = max(dp[nod], dp[nod] + dp[vec]);
            if(dp[nod] > maxm) maxm = dp[nod];
        }
    }
}
int main()
{
    int n,i,j;
    fin>>n;
    for(i=1; i<=n;i++) fin>>c[i];
    for(i=1; i<n; i++)
    {
        int a,b;
        fin>>a>>b;
        L[a].push_back(b);
        L[b].push_back(a);
    }
    //fac dfs dintr-un nod arbitrar
    dfs(1);
    fout<<maxm;
	return 0;
}