#include <fstream>
#include <vector>

using namespace std;
ifstream cin("asmax.in");
ofstream cout("asmax.out");
const int DIM = 16001;
int t[DIM], val[DIM], d[DIM], c[DIM], viz[DIM];
vector<int> a[DIM];
int n;
void bfs(int x0);
int main()
{
    int maxi = -1, imax;
    cin >> n;
    for(int i = 1; i <= n; ++i)
    {
        cin >> val[i];
        if(val[i] > maxi)
        {
            maxi = val[i];
            imax = i;
        }
    }
    for(int i = 1; i < n; ++i)
    {
        int x, y;
        cin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    bfs(imax);
    return 0;
}

void bfs(int x0)
{
    int nod, u, p, smax = -1, sum = 0;
    d[x0] = val[x0];
    viz[x0] = 1;
    p = u = 0;
    c[u++] = x0;
    while(p <= u)
    {
        nod = c[p++];
        sum += val[nod];
        if(sum > smax)
            smax = sum;
        for(int i = 0; i < a[nod].size(); ++i)
        {
            if(!viz[a[nod][i]])
            {
                d[a[nod][i]] = d[nod] + val[a[nod][i]];
                c[u++] = a[nod][i];
                viz[a[nod][i]] = 1;
            }
        }
    }
    cout << smax << ' ';
}