n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
c = list(map(int, input().split()))
ans = 0

for i in range(n):
    ans = b[a[i] - 1]
    if 1 <= i and a[i] - a[i - 1] == 1:
        ans += c[a[i-1] - 1]
print(ans)
