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

print(res)