#include <fstream>

using namespace std;
ifstream in ("asmax.in");
ofstream out ("asmax.out");
const int N=16003;
int lst[N*2],urm[N*2],vf[N*2],nr,v[N],s,smax=-2000000000;
bool viz[N];
void adauga(int x,int y)
{
    nr++;
    vf[nr]=y;
    urm[nr]=lst[x];
    lst[x]=nr;
}

void dfs(int x)
{
    viz[x]=true;
    int p=lst[x],y;
    while (p)
    {
        y=vf[p];
        if (!viz[y])
        {
            dfs(y);
            if (v[y]>=0)
                v[x]+=v[y];
        }
        p=urm[p];
    }
    if (v[x]>smax)
        smax=v[x];
}

int main()
{
    int n;
    in>>n;
    for (int i=1;i<=n;i++)
        in>>v[i];
    int x,y;
    while (in>>x>>y)
    {
        adauga(x,y);
        adauga(y,x);
    }
    dfs(1);
    out<<smax;
    return 0;
}