n = int(input())
alis = list(map(int, input().split()))
blis = list(map(int, input().split()))
clis = list(map(int, input().split()))
cache = 0
ans = 0
if n == 2 and alis[0] ==1:
    ans = sum([blis[0] + blis[1] + clis[0]])
else:
    for i in range(n):
        a = alis[i]
        b = blis[a - 1]
        ans += b
        if cache + 1 == a:
            ans += clis[a - 2]
        cache = a
print(ans)