import sys
input=lambda: sys.stdin.readline().rstrip()
n=int(input())
A=[int(i) for i in input().split()]
B=[int(i) for i in input().split()]

edge=[[] for i in range(n)]
for i in range(n-1):
  a,b=map(int,input().split())
  edge[a-1].append(b-1)
  edge[b-1].append(a-1)
inf=float("inf")
Par=[inf]*n
Par[0]=-1
Deg=[0]*n
Deg[0]=0
Chk=[0]
while Chk:
  c=Chk.pop()
  for next in edge[c]:
    if Par[next]==inf:
      Par[next]=c
      Deg[next]+=1
      Chk.append(next)
from collections import deque
TS=list(v for v in range(n) if Deg[v]==0)
D=deque(TS)
while D:
  v=D.popleft()
  for t in edge[v]:
    if t!=Par[v]:
      Deg[t]-=1
      if Deg[t]==0:
        D.append(t)
        TS.append(t)
P=[[0]*2 for _ in range(n)]
for i in range(n)[::-1]:
	cur=TS[i]
	Chd=[]
	for c in edge[cur]:
		if c!=Par[cur]:
			Chd.append(c)
	if not Chd:
		P[cur][0]=A[cur]
	else:
		for c in Chd:
			P[cur][0]+=max(P[c][0],P[c][1])
			P[cur][1]+=max(P[c][0],P[c][1]+B[cur]+B[c])
		P[cur][0]+=A[cur]
print(max(P[0]))