#include<bits/stdc++.h>
#define N 16050

using namespace std;

int n,rs,s,a[N];
int dp[N];
vector<int>V[N];
void DFS(int x, int pr) {
    for (auto it:V[x]) {
        if (it!=pr) {
            DFS(it,x);
            if (dp[it]>0) dp[x]+=dp[it];
        }
    }
    dp[x]+=a[x];
    rs=max(rs,dp[x]);
}

int main() {
    ifstream cin("asmax.in");
    ofstream cout("asmax.out");
    cin>>n;
    for (int i=1; i<=n; ++i) cin>>a[i], s+=a[i];
    for (int i=1; i<n; ++i) {
        int x,y; cin>>x>>y;
        V[x].push_back(y);
        V[y].push_back(x);
    }
    rs=s;
    DFS(1,-1);
    cout<<rs;

    return 0;
}