#include <cstdio>
#include <iostream>
#include <sstream>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
using namespace std;
#define ll long long
#define _cle(m, a) memset(m, a, sizeof(m))
#define repu(i, a, b) for(int i = a; i < b; i++)
#define repd(i, a, b) for(int i = b; i >= a; i--)
#define sfi(n) scanf("%d", &n)
#define sfl(n) scanf("%lld", &n)
#define pfi(n) printf("%d\n", n)
#define pfl(n) printf("%lld\n", n)
#define MAXN 6005
int w[MAXN];
bool f[MAXN] = {false};
vector<int> v[MAXN];
int d[MAXN][2];
bool vis[MAXN] = {false};
void dp(int root)
{
    if(vis[root]) return ;
    vis[root] = true;
    int siz = v[root].size();
    repu(i, 0, siz) dp(v[root][i]);

    repu(i, 0, siz)
    {
        d[root][0] += max(d[v[root][i]][1], d[v[root][i]][0]);
        d[root][1] += d[v[root][i]][0];
    }
    return ;
}
int main()
{
    int n;
    while(~sfi(n))
    {
        _cle(vis, false);
        _cle(f, false);
        repu(i, 1, n + 1)
        {
            sfi(w[i]);
            v[i].clear();
            d[i][0] = 0;
            d[i][1] = w[i];
        }
        int x, y;
        while(sfi(x), sfi(y), x + y)
        {
            v[y].push_back(x);
            f[x] = true;
        }
        int root;
        repu(i, 1, n + 1) if(!f[i])
        {
            root = i;
            break;
        }
        dp(root);
        pfi(max(d[root][0], d[root][1]));
        //repu(i, 1, n + 1) printf("%d %d\n", d[i][0], d[i][1]);
    }

    return 0;
}