#include <fstream>
#include <vector>
#include <bitset>
using namespace std;

ifstream is("asmax.in");
ofstream os("asmax.out");

int n, a, b, answ = -0x3f3f3f3f;
vector<int> v, smax;
vector<vector<int> > g;
bitset<16001> ok;

void DF(int k);

int main()
{
    is >> n;
    v.resize(n + 1);
    smax.resize(n + 1);
    g.resize(n + 1);
    for ( int i = 1; i <= n; ++i )
    {
        is >> v[i];
        smax[i] = v[i];
    }
    for ( int i = 1; i < n; ++i )
    {
        is >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    DF(1);
    for ( int i = 1; i <= n; ++i )
        if ( smax[i] > answ )
            answ = smax[i];
    os << answ;
    is.close();
    os.close();
    return 0;
}

void DF(int k)
{
    ok[k] = true;
    for ( auto& i : g[k] )
        if ( !ok[i] )
        {
            DF(i);
            if ( smax[i] > 0 )
                smax[k] += smax[i];
        }
}