n=int(input())
a = list(map(int,input().split()))
b= list(map(int,input().split()))
c= list(map(int,input().split()))
score=0
m=-1
for i in a:
  if(i-m==1):
    score+=c[i-2]
  score+=b[i-1]
  m=i
print(score)