N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
C=list(map(int,input().split()))
s=0
for i in range(N):
  if i>=2 and A[i]==A[i-1]+1:
    s=s+B[A[i]-1]+C[i-2]
  else:
    s=s+B[A[i]-1]
print(s)