n=int(input())
a=[int(i) for i in input().split()]
b=[int(i) for i in input().split()]
c=[int(i) for i in input().split()]
ans=sum(b)
pre=0
for i in range(n):
    tabeta=a[i]
    if tabeta==pre+1:
        ans+=c[pre-1]
    pre=tabeta
print(ans)