import sys
input = sys.stdin.readline

N=int(input())
A=[0]+list(map(int,input().split()))
B=[0]+list(map(int,input().split()))

E=[[] for i in range(N+1)]

for i in range(N-1):
    x,y=map(int,input().split())
    E[x].append(y)
    E[y].append(x)

QUE=[1] 
Parent=[-1]*(N+1)
Parent[1]=N+1
TOP_SORT=[] # トポロジカルソート

while QUE:
    x=QUE.pop()
    TOP_SORT.append(x)
    for to in E[x]:
        if Parent[to]==-1:
            Parent[to]=x
            QUE.append(to)

DP0=[-1<<100]*(N+1)
DP1=[-1<<100]*(N+1)

for x in TOP_SORT[::-1]:
    if x!=1 and len(E[x])==1:
        DP0[x]=A[x]
        DP1[x]=0

    else:
        S=0
        for to in E[x]:
            if to==Parent[x]:
                continue
            S+=max(DP0[to],DP1[to])

        DP0[x]=S+A[x]

        S2=0
        for to in E[x]:
            if to==Parent[x]:
                continue
            S2+=max(DP1[to]+B[x]+B[to],DP0[to]+B[x]+B[to]-A[to],DP0[to])

        DP1[x]=S2

print(max(DP0[1],DP1[1]))