#include <cstdio>#include <cstring>#include <cmath>#include <algorithm>#include <climits>#include <string>#include <iostream>#include <map>#include <cstdlib>#include <list>#include <set>#include <queue>#include <stack>using namespace std;typedef long long LL;const int maxn = 6000 + 5;int fa[maxn],n,c[maxn];vector<int> ch[maxn];int f[maxn][2];int dfs(int now,bool prev) {    int m  = ch[now].size(),ret;    if(m == 0) return prev ? 0 : c[now];    int &note = f[now][prev];    if(note != -1) return note;    int ret1 = c[now],ret2 = 0;    for(int i = 0;i < m;i++) {        int id = ch[now][i];        ret1 += dfs(id,1);         ret2 += dfs(id,0);    }    if(prev) ret =  ret2;    else ret =  max(ret1,ret2);    return note = ret;}int main() {    while(scanf("%d",&n) != EOF) {        memset(f,-1,sizeof(f));        memset(fa,0,sizeof(fa));        for(int i = 1;i <= n;i++) scanf("%d",&c[i]);        for(int i = 1;i <= n;i++) ch[i].clear();        int a,b;        while(scanf("%d%d",&a,&b), a) {            fa[a] = b;            ch[b].push_back(a);        }        int root;         for(int i = 1;i <= n;i++) if(fa[i] == 0) root = i;        int ret = dfs(root,0);        printf("%d\n",ret);    }    return 0;}