#include <bits/stdc++.h>

using namespace std;
int dp[16001],v[16001],sup;
vector<vector<int>> m(16001);
int n,a,b;
int vis[16001];
void dfs(int nod)
{
    int vec;
    vis[nod]=1;
    dp[nod]=v[nod];
    for(int i=0;i<m[nod].size();i++)
    {
        vec=m[nod][i];
        if(!vis[vec])
        {
            dfs(vec);
            if(dp[vec]>0)
            {
                dp[nod]=dp[nod]+dp[vec];
            }
        }
    }
    if(sup<dp[nod])sup=dp[nod];
}
int main()
{
    freopen("asmax.in","r",stdin);
    freopen("asmax.out","w",stdout);
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>v[i];
    }
    for(int i=1;i<=n;i++)
    {
        cin>>a>>b;
        m[a].push_back(b);
        m[b].push_back(a);
        dp[i]=-1;
    }
    sup=-10000000;
    dfs(1);
    cout<<sup;

    return 0;
}