#include <fstream>
#include <vector>


using namespace std;


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

const int N =  16001;

vector <int> a[N];

int n,val[N],x,y,maxx=-1e9,scor[N],v[N];

void dfs(int nod)
{
    v[nod] = 1;
    scor[nod] = val[nod];
    for(auto y: a[nod])
    {
        if(!v[y])
        {
            dfs(y);
            if(scor[y]>0)
                scor[nod]+=scor[y];
        }
    }
}

void citire()
{
    fin>>n;
    for(int i=1;i<=n;i++)
        fin>>val[i];
    while(fin>>x>>y)
    {
        a[x].push_back(y);
        a[y].push_back(x);
    }

}


int main()
{
    citire();
    dfs(1);
    for(int i=1;i<=n;i++)
    {
        maxx=max(scor[i],maxx);
    }
    fout<<maxx;
    return 0;
}