i = int(input())

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

res = sum(b)

for j in range(1,i):
    res += b[a[j]-1]
    if a[j] - a[j-1] == 1:
        res += c[a[j-1]-1]
print(res)