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