#include <fstream>
#include <cstring>
#include <vector>
using namespace std;
ifstream fin("asmax.in");
ofstream fout("asmax.out");
const int NMax = 16000;
int N,Value[NMax + 5],Max = -1001;
vector <int> G[NMax + 5];
int DP[NMax + 5],Sum[NMax + 5],Use[NMax + 5];
void Read()
{
    fin >> N;
    for(int i = 1; i <= N; ++i)
        fin >> Value[i];
    for(int i = 1 ;i < N; ++i)
    {
        int x,y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DFS(int Nod)
{
    Use[Nod] = 1;
    DP[Nod] = -1001;
    Sum[Nod] = Value[Nod];
    for(auto Vecin : G[Nod])
    {
        if(!Use[Vecin])
        {
            DFS(Vecin);

            DP[Nod] = max(DP[Nod],DP[Vecin]);
            Sum [Nod] += Sum[Vecin];
        }
    }
    DP[Nod] = max(DP[Nod],Sum[Nod]);
}

int main()
{
    Read();
    for(int i = 1; i <= N; ++i)
    {
        memset(Use,0,sizeof(Use));
        memset(Sum,0,sizeof(Sum));
        memset(DP,0,sizeof(DP));
        DFS(i);
        Max = max(Max,DP[i]);
    }
    fout << Max << "\n";
    return 0;
}