N = int(input())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
C = list(map(int, input().split()))
f = False
x = 0
for i in range(N):
  bx = B[A[i]-1]
  if f:
    x += bx + C[A[i-1]-1]
    f = False
    if i+1 < len(A) and A[i] + 1 in A:
      f = True
  else:
    if i+1 < len(A) and A[i] + 1 in A:
      f = True
      x += bx
    else:
      x += bx
print(x)