#include <iostream>
#include <vector>
#include <fstream>
#define MAX 16002
using namespace std;
int n,val[MAX],x,y,rd,f[MAX],smax,s[MAX],viz[MAX];
vector<int> v[MAX];

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

void dfs(int nod){
    viz[nod] = 1;
    s[nod] = val[nod];
    for(int i = 0; i < v[nod].size(); i++){
        int vecin = v[nod][i];
        if(viz[vecin] == 0){
            dfs(vecin);
            s[nod] += s[vecin];
            /// suma sus = s[rd]-s[nod]
            /// suma jos = s[nod]
            smax = max(smax, max(s[rd]-s[nod], s[nod]));
        }
    }
}

int main()
{
    fin >> n;
    for(int i = 1; i <= n; i++){
        fin >> val[i];
    }
    for(int i = 1; i < n; i++){
        fin >> x >> y;
        f[y] = 1;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    /// determinam radacina
    for(int i = 1; i <= n; i++){
        if(f[i] == 0){
            rd = i;
            break;
        }
    }
    dfs(rd);
    fout << smax << "\n";
    return 0;
}