size = gets.to_i
seq = gets.split(" ").map(&:to_i)

count = 0
1.upto(size - 1) do |i|
  0.upto(i) do |j|
    if seq[j] > seq[i]
      count += 1
      seq[j], seq[i] = seq[i], seq[j]
    end
  end
end

p count