#include <fstream>
#include <vector>
#include <bitset>
using namespace std;
ifstream f("asmax.in");
ofstream g("asmax.out");
int n,val[16001],i,MAX,poz,x,y,s[16001],sum,MAXIM;
vector <int> v[16001];
bitset <100001> viz;
void dfs(int i)
{
    int j;
    viz[i]=true;
    for (j=0;j<v[i].size();j++)
        if (viz[v[i][j]]==false && val[v[i][j]]>0)
        dfs(i+1),s[x]+=val[v[i][j]];
    MAXIM=max(s[x],MAXIM);

}
int main()
{
    f>>n;
    for (i=1;i<=n;i++)
        {f>>val[i];
        }
   for (i=1;i<=n-1;i++)
   {
       f>>x>>y;
       v[x].push_back(y);
       v[y].push_back(x);
   }
   viz[1]=true;
   dfs(1);
   g<<MAXIM;
    return 0;
}