#include <fstream>
#include <vector>
using namespace std;

ifstream cin("asmax.in");
ofstream cout("asmax.out");

int dp[16002],maxim=-1e9;
vector<vector<int>> v;
vector<bool> checked;

void dfs(int nod){
    checked[nod]=true;

    for(int i=0;i<v[nod].size();i++){
        if(checked[v[nod][i]]==false){
        dfs(v[nod][i]);

        if(dp[v[nod][i]]>0)
        dp[nod]+=dp[v[nod][i]];
        }
    }
    maxim=max(maxim,dp[nod]);
}

int main()
{
    int n;
    cin>>n;
    v.resize(n+1);
    checked.resize(n+1,false);

    for(int i=1;i<=n;i++)
    cin>>dp[i];

    int a,b;
    while(cin>>a>>b){
        v[a].push_back(b);
        v[b].push_back(a);
    }

    dfs(1);
    cout<<maxim;
}