n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
c = list(map(int, input().split()))
suf = 0
for i in range (n):
  men1 = a[i]
  men2 = a[i + 1] 
  suf += b[men1]
  if (men1 != n - 1 )and(men1 + 1 == men2):
    suf += c[men1]
print(suf)
