n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
c = list(map(int, input().split()))
s = 0
for i in range(n):
 s += b[a[i]-1]
 if a[i] == a[i-1] + 1 and i != 0:
     s += c[i-2]
print(s)
