import sys
sys.setrecursionlimit(100050)

N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
dp = [[0, 0] for _ in range(N)]

E = [[] for _ in range(N)]
for _ in range(N - 1):
    u, v = map(int, input().split())
    u -= 1
    v -= 1
    E[u].append(v)
    E[v].append(u)

def dfs(x, p=-1):
    ret = 0
    cnt = 0
    for y in E[x]:
        if y == p:
            continue
        dfs(y, x)
        dp[x][0] += max(dp[y])
        dp[x][1] += max(dp[y][1] + B[x] + B[y],dp[y][0])
    dp[x][0] += A[x]

dfs(0)
print(max(dp[0]))