#include<bits/stdc++.h>
using namespace std;
ifstream f("asmax.in");
ofstream g("asmax.out");

vector<int>G[16001];
int cost[16001],v[16001],mx=-10000;
int n,x,y;
bool viz[1000001];
void DFS(int node)
{
    viz[node]=1;
    cost[node]=v[node];
    for(vector<int>::iterator it=G[node].begin();it<G[node].end();++it)
    {
        if(viz[*it]==0)
        {
            DFS(*it);
            if(cost[*it]>0)
                cost[node]+=cost[*it];
        }
    }
    mx=max(mx,cost[node]);
}

int main()
{
    f>>n;
    for(int i=1;i<=n;++i)
        f>>v[i];
    while(f>>x>>y)
    {
        G[x].push_back(y);
        G[y].push_back(x);
    }
    DFS(1);
    g<<mx;
}