#include <fstream>
#include <vector>
#define N 16005
using namespace std;

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

int n;
int cost[N];
bool vizitat[N];
vector<vector<int> >graf(N);

int dfs(int nod){
    vizitat[nod] = true;

    for(size_t i = 0; i < graf[nod].size(); ++i)
        if(!vizitat[graf[nod][i]])
            cost[nod] += dfs(graf[nod][i]);

    if(cost[nod] < 0) return 0;
    else return cost[nod];

}

int main()
{
    in>>n;
    for(int i = 1; i <= n; ++i)
        in>>cost[i];

    for(int i = 1; i <= n - 1; ++i){
        int x, y;
        in>>x>>y;

        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    dfs(1);

    int costMax = cost[1];

    for(int i = 2; i <= n; ++i)
        costMax = max(costMax, cost[i]);

    out<<costMax<<" ";

    in.close();
    out.close();
    return 0;
}