sum = 0
n = int(input())
l = [list(map(int, input().split()) for i in range(3))]

for i in range(n):
  sum = sum + l[1][i]
  if l[0][i+1] - l[0][i] == 1:
    sum = sum + l[2][i]
sum = sum + l[1][n]
print(sum)