// poj2342

#include<algorithm>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<cstdio>

#include<cmath>

#define LL long long

#define inf 2147483647

#define Pi 3.1415926535898

#define fre(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout);

using namespace std;

LL getint() {

    LL x=getchar(),t=0,f=1;if (x>'9' || x<'0') {if (x=='-') f=-1;x=getchar();}

    while (x>='0' && x<='9') {t=t*10+x-48;x=getchar();}return t*f;

}

void putint(LL x) {

    if (x<0) putchar('-'),x=-x;

    if (x>9) putint(x/10);putchar(x%10+48);

}

int dp[1000010][5],n,f[1000010],x,y;

bool b[1000010];

void tree_dp(int u) {

    b[u]=1;

    for (int i=1;i<=n;i++)

        if (!b[i] && f[i]==u) {

            tree_dp(i);

            dp[u][1]+=dp[i][0];

            dp[u][0]+=max(dp[i][1],dp[i][0]);

        }

}

int main() {

    scanf("%d",&n);

    for (int i=1;i<=n;i++) scanf("%d",&dp[i][1]);

    for (int i=1;i<=n-1;i++)

        scanf("%d%d",&x,&y),f[x]=y;

    int u=n;

    while (f[u]) u=f[u];

    tree_dp(u);

    printf("%d",max(dp[u][1],dp[u][0]));

    return 0;

}