n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
c = list(map(int, input().split()))
ans = 0

for i in range(n):
  ans += b[a[i]-1]
  if i < n-1:
    if a[i] == a[i+1]-1:
      ans += c[i-1]
    
print(ans)