a.rb

#!/usr/bin/env ruby

class Node
  attr_accessor :size, :num, :left, :right

  def initialize(n)
    self.size = 1
    self.num = n
    self.left = nil
    self.right = nil
  end

  def insert(node)
    self.size += 1
    if self.num < node.num
      if self.right.nil?
        self.right = node
        return 0
      else
        return self.right.insert(node)
      end
    else
      if self.left.nil?
        self.left = node
        return self.size - 1
      else
        return self.left.insert(node) + 1 + (self.right.nil? ? 0 : self.right.size)
      end
    end
  end
end

def solve(lis)
  sum = 0
  root = Node.new lis.shift
  lis.each do |e|
    sum += root.insert(Node.new(e))
  end
  sum
end

if __FILE__ == $0
  lis = ARGF.read.split
  puts solve(lis)
end