#include <fstream>
#include <vector>
using namespace std;
ifstream cin ("asmax.in");
ofstream cout ("asmax.out");
struct ura{
    int val;
    vector <int> fi;
};
vector<ura> v;
int maxi=-1;
int sum(int i)
{
    int suma=v[i].val;
    for(int j=0;j<v[i].fi.size();j++)
    {
        suma+=max(0,sum(v[i].fi[j]));  
    }
    maxi=max(maxi,suma);
    return suma;
}
int main()
{
    int n;
    cin>>n;
    v.resize(n+1);
    for(int i=1;i<=n;i++)
    {
        cin>>v[i].val;
    }
    vector <bool> startfind;
    startfind.resize(n+1);
    for(int i=1;i<=n-1;i++)
    {
        int a,b;
        cin>>a>>b;
        v[a].fi.push_back(b); 
        startfind[a]=true;
        startfind[b]=true;
    }
    int strt;
    for(int i=1;i<=n;i++)
    {
        if(!startfind[i])
            strt=i;
    }
    strt=sum(strt);
    cout<<maxi;
    return 0;
}