#include<iostream>

#include<string.h>

#include<stdio.h>

#include<vector>

using namespace std;

const int maxa = ;

int n;

vector< int> xiashu[maxa];

int dp[maxa][];

int v[maxa];

int du[maxa];

int dfs(int x, int zai){

    int maxn = ;

    int sum = ;

    if(dp[x][zai])

        return dp[x][zai];

    for(int i = ;i < xiashu[x].size(); i++){

        int k = xiashu[x][i];

        sum += dfs(k, );

    }

    maxn = sum;

    if(zai)

        return dp[x][zai] = maxn;

    sum = ;

    for(int i = ; i < xiashu[x].size(); i++){

        int k = xiashu[x][i];

        sum += dfs(k, );

    }

    return dp[x][zai] = max(maxn, sum +v[x]);

}

int main(){

    while(scanf("%d", &n)!=EOF){

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

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

        }

        memset(dp, , sizeof(dp));

        memset(du, , sizeof(du));

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

            xiashu[i].clear();

        int x, y;

        while(){

            scanf("%d%d", &x, &y);

            if(!y && !x)

                break;

            xiashu[y].push_back(x);

            du[x]++;

        }

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

            if(du[i]==)

                printf("%d\n", dfs(i, ));

        }

    }

}