#include <fstream>
#include <vector>

using namespace std;

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

int n,sol[16001],val[16001];
bool vizi[16001];
vector<int>a[16001];

void dfs(int nod)
{
    vizi[nod]=true;
    sol[nod]=val[nod];
    for(auto y:a[nod])
    {
        if(!vizi[y])
        {
            dfs(y);

            if(sol[y]>0)
                sol[nod]+=sol[y];
        }
    }
}

int main()
{
    in>>n;
    for(int i=1; i<=n; i++)
        in>>val[i];
    int x,y;
    while(in>>x>>y)
    {
        a[x].push_back(y);
        a[y].push_back(x);
    }
    dfs(1);
    int sum=-1001;
    for(int i=1; i<=n; i++)
    {

        sum=max(sum,sol[i]);
    }
    out<<sum;
    return 0;
}