N = gets.to_i
P = gets.split.map(&:to_i)
rounds = Hash.new

P.each.with_index(1) do |x, i|
  rounds[x] = i
end

ans = 0
i = N
sum = (1..N).sum

while i >= 1
  score = sum - 2 * rounds[i]
  ans = score if ans < score
  sum -= rounds[i]
  i -= 1
end

puts ans