#include<bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops,inline")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define setinf(x) memset(x,0x3f3f3f3f,sizeof(x));
#define set0(x) memset(x,0,sizeof(x));
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define INF 0x3f3f3f3f
#define vi vector<int>
#define ll long long
#define vll vector<ll>
#define pb push_back
#define fi first
#define se second
#define DD 16001
#define nl '\n'
using namespace std;
const string file="asmax";
ifstream f(file+".in");
ofstream g(file+".out");
//#define f cin
//#define g cout
int n;
vi v[DD];
int dp[DD],a[DD];
void dfs(int x, int p) {
    dp[x]=a[x];
    for (auto e:v[x]) {
        if (e==p) continue;
        dfs(e,x);
        dp[x]=max(dp[x],dp[x]+dp[e]);
    }
}
int main(){
    f>>n;
    for (int i=1; i<=n; ++i) {
        f>>a[i];
    }
    for (int i=1; i<n; ++i) {
        int x,y;
        f>>x>>y;
        v[x].pb(y);
        v[y].pb(x);
    }
    dfs(1,0);
    g<<*max_element(dp+1,dp+n+1);
    system("pause");
    return 0;
}