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