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

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

void Read();
void Dfs(int k);

int n, m;
int maxim = -0x3f3f3f3f;
vector<vector<int>> g;
vector<bool> v;
vector<int> sum;

int main()
{
    Read();
    Dfs(1);
    for(int i = 1; i <= n; ++i)
    {
        maxim = max(maxim, sum[i]);
    }
    os << maxim;
    is.close();
    os.close();
    return 0;
}

void Read()
{
    is >> n;
    g = vector <vector<int>>(n+1);
    v = vector<bool>(n + 1);
    sum = vector<int>(n + 1);
    int x, y;
    for(int i = 1; i <= n; ++i)
    {
        is >> x;
        sum[i] = x;
    }
    for(int i = 1; i <= n-1; ++i)
    {
        is >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);

    }
}

void Dfs(int k)
{
    v[k] = true;
    for (const auto& x : g[k])
    {
        if( v[x]) continue;
        Dfs(x);
        if(sum[x] > 0 )
            sum[k] += sum[x];
    }
}