import sys
sys.setrecursionlimit(2*10**5)
N=int(input())
dp1=[0]+list(map(int,input().split()))
dp2=[0]*(N+1)
b=[0]+list(map(int,input().split()))
g=[[] for _ in range(N+1)]
for _ in range(N-1):
    u,v=map(int,input().split())
    g[u].append(v)
    g[v].append(u)
def dfs(v,p):
    for u in g[v]:
        if u==p:
            continue
        dfs(u,v)
        dp1[v]+=max(dp1[u],dp2[u])
        dp2[v]+=max(dp1[u],dp2[u]+b[u]+b[v])
dfs(1,0)
print(max(dp1[1],dp2[1]))