lg1352

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>
#define rep(i,x,y) for(register int i=x;i<=y;++i)
#define repd(i,x,y) for(regsiter int i=x;i>=y;--i)
using namespace std;
const int N=1e4;
int fa[N],r[N],dp[N][2],vis[N];
int n,root=1;
template <typename T>inline void (T&x){
    x=0;char c;int sign=1;
    do{ c=getchar(); if(c=='-')sign=-1;}while(c<'0'||c>'9');
    do{ x=x*10+c-'0'; c=getchar();}while(c>='0'&&c<='9');
    x*=sign;
}


void tdp(int node){
    vis[node]=1;
    rep(i,1,n)if(!vis[i]&&fa[i]==node){
        tdp(i);
        dp[node][1]+=dp[i][0];
        dp[node][0]+=max(dp[i][1],dp[i][0]);
    }
}

int main(){
    read(n);
    rep(i,1,n)read(dp[i][1]);
    rep(i,1,n-1){
        int x,y;
        read(x);read(y);
        fa[x]=y;
    }
    rep(i,1,n)if(!fa[i]){
        root=i;break;	
    }
    tdp(root);
    printf("%d",max(dp[root][1],dp[root][0]));
    return 0;
}