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