from collections import defaultdict
import sys
sys.setrecursionlimit(10 ** 6)

N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
adj = defaultdict(list)
for _ in range(N-1):
    U, V = map(lambda x: int(x)-1, input().split())
    adj[U].append(V)
    adj[V].append(U)


def tree_dp(v, par):
    dp0 = 0     # 頂点 v を削除しない
    dp1 = A[v]  # 頂点 v を削除する

    for to in adj[v]:
        if to == par: continue

        r_dp0, r_dp1 = tree_dp(to, v)

        dp0 += max(r_dp0 + B[v] + B[to], r_dp1)
        dp1 += max(r_dp0, r_dp1)

    return dp0, dp1


dp0, dp1 = tree_dp(0, -1)
ans = max(dp0, dp1)
print(ans)