N = gets.to_i
A = gets.split.map &:to_i
width = (A.sum**0.5).floor*2-1
add = sub = 0
A.map.with_index{|n, i|
  height = [width - i, i+1].min
  diff = height - n
  if diff > 0
    add += diff
  else
    sub -= diff
  end
}
p (add - sub).abs + [add, sub].min