#include <fstream>
#include <vector>
using namespace std;
ifstream cin("asmax.in");
ofstream cout("asmax.out");
const int N = 100005;
vector <int>v[N];
bool viz[N];
long long sum[N];
long long maxim = 0;
int n,m;
void dfs(int nod){
    viz[nod] = 1;
    int i;
    for(i = 0;i < v[nod].size();i++){
        if(!viz[v[nod][i]]){
            dfs(v[nod][i]);
            if(sum[v[nod][i]] > 0)
               sum[nod] += sum[v[nod][i]];
        }
    }
    if(sum[nod] > maxim)
        maxim = sum[nod];
}
int main()
{
    int x,y,cnt = 0,i;
    cin >> n;
    for(i = 1;i <= n;i++)
        cin >> sum[i];
    for(i = 1;i <= n-1;i++){
        cin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    dfs(1);
    cout << maxim;
    return 0;
}