N = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
C = list(map(int,input().split()))
  
bj=0
newlist=0
for j in A:
  newlist += B[j-1]
  if j-bj==1: 
    newlist += C[j-2]
  bj=j

print(newlist)