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