#include <fstream>
#include <vector>
#include <climits>
using namespace std;
ifstream in("asmax.in");
ofstream out("asmax.out");
const int Nmax = 16005;
vector <int> G[Nmax];
int n, Cost[Nmax], CostMax[Nmax];
int sol = INT_MIN;
int x,y;
void DFS(int nod, int tata)
{
    for(int i = 0; i < (int)G[nod].size(); i++)
    {
        int v = G[nod][i];
        if(v!=tata)
        {
            DFS(v,nod);
        }
    }
    if(CostMax[nod] + Cost[nod] > Cost[nod]) CostMax[tata] += CostMax[nod] + Cost[nod];
}
int main()
{
    in>>n;
    for(int i = 1; i <= n; i++)
        in>>Cost[i];
    for(int i = 1; i < n; i++)
    {
        in>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    DFS(1,0);
    for(int i = 1; i <= n; i++)
    {
        if(CostMax[i] + Cost[i] > sol) sol = CostMax[i] + Cost[i];
    }
    out<<sol;
    return 0;
}