Public Class Program
  Shared Sub Main()
    Dim n As Integer = Integer.Parse(Console.ReadLine())
    Dim a As Integer() = Array.ConvertAll(Of String, Integer)(Console.ReadLine().Split(" "), AddressOf Integer.Parse)
    Dim b As Integer() = Array.ConvertAll(Of String, Integer)(Console.ReadLine().Split(" "), AddressOf Integer.Parse)
    Dim c As Integer() = Array.ConvertAll(Of String, Integer)(Console.ReadLine().Split(" "), AddressOf Integer.Parse)
    Dim ans As Integer = 0
    Dim before As Integer = -1
    For i As Integer = 0 To n - 1
      ans += b(a(i) - 1)
      If a(i) = before + 1 Then ans += c(before - 1)
      before = a(i)
    Next
    Console.WriteLine(ans.ToString())
  End Sub
End Class