#include <iostream>#include <cstring>#include <cstdio>#include <cstdlib>#include <cmath>#include <string>#include <vector>#include <list>#include <map>#include <queue>#include <stack>#include <bitset>#include <algorithm>#include <numeric>#include <functional>using namespace std;#define LL long long#define DB double#define N 100005const int INF = 0x3f3f3f3f;const LL INFF = 1LL << 60;const DB EPS = 1e-9;const DB OO = 1e15;const DB PI = acos(-1.0);int val[N],dp[N][2],f[N];vector<int>G[N];void dfs(int rt){    int i,len = G[rt].size();    dp[rt][1] = val[rt];    for(i = 0 ; i < len ; i++)        dfs(G[rt][i]);    for(i = 0 ; i < len ; i++)    {        dp[rt][0]+=max(dp[G[rt][i]][0],dp[G[rt][i]][1]);        dp[rt][1]+=dp[G[rt][i]][0];    }}int main(){    int n,i,j,a,b;    while(~scanf("%d",&n))    {        memset(G,0,sizeof(G));        for(i = 1 ; i <= n ; i++)        {            scanf("%d",&val[i]);            f[i] = -1;            dp[i][0] = dp[i][1] = 0;        }        while(scanf("%d %d",&a,&b),a+b)        {            f[a] = b;            G[b].push_back(a);        }        a = 1;        while(f[a]!=-1) a = f[a];        dfs(a);        printf("%d\n",max(dp[a][0],dp[a][1]));    }    return 0;}