# include <fstream>
# include <vector>
# define DIM 16010
# define INF -2000000000
using namespace std;
ifstream fin("asmax.in");
ofstream fout("asmax.out");
vector <int> Lista[DIM];
int Marcat[DIM],d[DIM],v[DIM],n,i,maxim=INF,x,y;
void dfs(int nc){
    int nv,s=0;
    Marcat[nc]=1;
    for(int i=0;i<Lista[nc].size();i++){
        nv=Lista[nc][i];
        if(Marcat[nv]==0){
            dfs(nv);
            if(d[nv]>0)
                s+=d[nv];
        }
    }
    d[nc]=v[nc]+s;
    if(d[nc]>maxim)
        maxim=d[nc];
}
int main () {
    fin>>n;
    for(i=1;i<=n;i++)
        fin>>v[i];
    for(i=1;i<=n;i++){
        fin>>x>>y;
        Lista[x].push_back(y);
        Lista[y].push_back(x);
    }
    dfs(1);
    fout<<maxim<<"\n";
    return 0;
}