import sys
def input(): return sys.stdin.readline().rstrip()
sys.setrecursionlimit(1000000)

n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
edge=[[]for _ in range(n)]
for _ in range(n-1):
  aa,bb=map(int,input().split())
  aa-=1
  bb-=1
  edge[aa].append(bb)
  edge[bb].append(aa)
dp=[[a[i],0]for i in range(n)]
def dfs(r,node):
  if len(edge[node])==1 and r!=-1:
    return dp[node]
  x=a[node]
  y=0
  for mode in edge[node]:
    if mode==r:continue
    xx,yy=dfs(node,mode)
    x+=max(xx,yy)
    y+=max(xx,b[node]+b[mode]+yy)
  return [x,y]
x,y=dfs(-1,0)
print(max(x,y))