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

score = 0

for i in range(0, N):
    score += B[A[i]-1]
    if i != 0 and A[i] == A[i-1] + 1:
        score += C[i-2]

print(score)