n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
c=list(map(int,input().split()))
ans=b[a[0]-1]
for i in range(1,n):
  eat=a[i]
  ans+=b[a[i]-1]
  if a[i]-a[i-1]==1:
    ans+=c[i-1]
print(ans)