#include <map>

#include <set>

#include <list>

#include <cmath>

#include <queue>

#include <stack>

#include <cstdio>

#include <vector>

#include <string>

#include <cctype>

#include <complex>

#include <cassert>

#include <utility>

#include <cstring>

#include <cstdlib>

#include <iostream>

#include <algorithm>

using namespace std;

typedef pair<int,int> PII;

typedef long long ll;

#define lson l,m,rt<<1

#define pi acos(-1.0)

#define rson m+1,r,rt<<11

#define All 1,N,1

#define read freopen("in.txt", "r", stdin)

const ll  INFll = 0x3f3f3f3f3f3f3f3fLL;

const int INF= 0x7ffffff;

const int mod =  ;

struct tree{

    int u,v,next;

} t[];

int par[],dp[][],n,head[],len,root;

void add(int a,int b){

    t[len].u=a;

    t[len].v=b;

    t[len].next=head[a];

    head[a]=len++;

}

void dfs(int root){

    for(int i=head[root];i!=-;i=t[i].next){

        int son=t[i].v;

        dfs(son);

        dp[root][]+=max(dp[son][],dp[son][]);

        dp[root][]+=dp[son][];

    }

}

int main()

{

    while(~scanf("%d",&n)){

        memset(par,,sizeof(par));

        memset(dp,,sizeof(dp));

        memset(head,-,sizeof(head));

        for(int i=;i<=n;++i)

            scanf("%d",&dp[i][]);

            int c,f;

            len=;

            while(scanf("%d%d",&c,&f)){

                if(c==&&f==)break;

               add(f,c);

               par[c]=;

            }

            for(int i=;i<=n;++i){

                if(!par[i]){

                    root=i;

                    break;

                }

            }

            dfs(root);

            printf("%d\n",max(dp[root][],dp[root][]));

    }

return ;

}