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):
  suf += b[a[i - 1] ]
  if (a[i] != n )and(a[i - 1]  + 1 == a[i]):
    suf += c[a[i - 1]]
print(suf)
