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

ifstream fin("asmax.in");
ofstream fout("asmax.out");

const int Inf = 0x3f3f3f3f;
using VI = vector<int>;
vector<VI> G;
VI v, sum;
vector<bool> s;
int N;
int smax = -Inf;

void Read();
void DF( int nod );

int main()
{
    Read();
    DF(1);

    fout << smax << '\n';

    fin.close();
    fout.close();
    return 0;
}

void Read()
{
    int x, y, i;

    fin >> N;
    G = vector<VI>(N + 1);
    sum = v = VI(N + 1);
    s = vector<bool>(N + 1);
    for ( i = 1; i <= N; ++i )
        fin >> v[i];

    for ( i = 1; i < N; ++i )
    {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void DF( int nod )
{
    s[nod] = true;
    sum[nod] = v[nod];

    for ( const auto& x : G[nod] )
        if ( !s[x] )
        {
            DF(x);
            if ( sum[x] > 0 )
                sum[nod] += sum[x];
        }

    smax = max( smax, sum[nod] );
}