#include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
const int N = 6010;
int last[N],ne[N],edge[N],cnt;
int ha[N];
bool HF[N];
int f[N][2];
void add(int a, int b){
    edge[cnt] = b;
    ne[cnt] = last[a];
    last[a] = cnt++;
}
void MZBZY(int root){
    f[root][1] = ha[root];
    for(int i = last[root];i != -1;i = ne[i]){
        MZBZY(edge[i]);
        f[root][0]+=max(f[edge[i]][0],f[edge[i]][1]);
        f[root][1]+=f[edge[i]][0];
    }
}
int main(){
    memset(edge,-1,sizeof edge);
    memset(last,-1,sizeof last);
    int n;
    cin>>n;
    for(int i = 1;i <= n;i ++){
        cin>>ha[i];
    }
    for(int i = 1;i <= n - 1;i ++){
        int a,b;
        cin>>a>>b;
        add(b,a);
        HF[a] = true;
    }
    int root = 1;
    while(HF[root]) root++;
    MZBZY(root);
    cout<<max(f[root][0],f[root][1]);
}