N  = gets.to_i
as = gets.split.map(&:to_i)

ans = 0
(N-1).downto(1) do | tgt |
  i = as.index(tgt+1)
  j = as.index(tgt)
  if i < j
    ans += 1
    as.delete_at(j)
    as.unshift(tgt)
  end
end

p ans