#include <bits/stdc++.h>
using namespace std;
const int NMAX = 16000;
vector<int>v[NMAX + 5];
int val[NMAX + 5], smax[NMAX + 5], maxim;
void dfs(int nod, int prov){
    for (int i = 0; i < v[nod].size(); i ++)
        if (v[nod][i] != prov)
            dfs(v[nod][i], nod);
    int s = 0;
    for (int i = 0; i < v[nod].size(); i ++)
        if (v[nod][i] != prov && val[v[nod][i]] > 0)
            s += val[v[nod][i]];
    val[nod] += s;
    maxim = max(maxim, val[nod]);
}
int main(){
    freopen("asmax.in", "r", stdin);
    freopen("asmax.out", "w", stdout);
    int n, m, i, a, b;
    scanf("%d", &n);
    for (i = 1; i <= n; i ++)
        scanf("%d", &val[i]);
    for (i = 1; i < n; i ++){
        scanf("%d%d", &a, &b);
        v[a].push_back(b);
        v[b].push_back(a);
    }
    maxim = -(1LL << 31) + 1;
    dfs(1, 0);
    printf("%d\n", maxim);
    return 0;
}