#include <iostream>
#include <fstream>
#define Nmax 16002
#include <algorithm>
#include <vector>

using namespace std;
ifstream fin("asmax.in");
ofstream fout("asmax.out");
vector <int> G[Nmax];
int viz[Nmax],DP[Nmax],MAX=-16000000;
void DFS(int nod,int father)
{
    viz[nod]=1;

    for(unsigned int i=0;i<G[nod].size();i++)
        if(!viz[G[nod][i]])
              DFS(G[nod][i],nod);

     //DP[nod]+=val[nod];
    DP[father]=max(DP[father],DP[father]+DP[nod]);

}

int main()
{
    int n,i;
    fin>>n;
    for(i=1;i<=n;i++)
        fin>>DP[i];
    int x,y;
    for(i=1;i<n;i++)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    viz[1]=1;
    DFS(1,0);

        sort(DP,DP+n+1);
        fout<<DP[n];

    return 0;
}