N=int(input())
A=list(map(int, input().split()))
B=list(map(int, input().split()))
C=list(map(int, input().split()))

ans=0
for i in range(N-1):
    if A[i]+2==A[i+1]:
        ans+=C[A[i]-1]
        
ans+=sum(B)

print(ans)
    