n = int(input())
a, b, c = [list(map(int, input().split())) for _ in range(3)]
ret = 0
for i in range(n):
    ret += b[a[i] - 1]
    if i > 0 and a[i] == a[i - 1] + 1:
        ret += c[a[i - 1] - 1]
print(ret)