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(N):
    Sum += B[A[i] - 1]
    if i > 1 & A[i] - A[i-1] == 1:
        Sum += C[A[i] - 2]
print(Sum)