N=gets.chomp.to_i
A=gets.chomp.split.map(&:to_i)
B=gets.chomp.split.map(&:to_i)
C=gets.chomp.split.map(&:to_i)

diff_a = []
(A.size-1).times do |i|
  diff_a << [A[i+1] - A[i],A[i]]
end

b_sum = B.inject(&:+)
diff_one_index = diff_a.select{|a| a.first == 1}.map(&:last)

additional = 0
diff_one_index.each do |n|
  additional += C[n-1]
end

puts b_sum+additional