def main():
    n = int(input())
    a_l = list(map(int, input().split()))
    b_l = list(map(int, input().split()))
    c_l = list(map(int, input().split()))
    res = 0
    pre = 1
    for a in a_l:
        res += b_l[a-1]
        if a - pre == 1:
            res += c_l[pre-1]
        pre = a
    print(res)

if __name__ == "__main__":
    main()