n = gets.to_i
a = Array.new(n)
(0..(n-1)).each do |i|
  a[i] = gets.to_i
end


if n == 2
  a = a.sort
  p a[1]-a[0]
  return
end

if n == 3
  a = a.sort
  p [(a[2]*2-a[0]-a[1]), (a[2]+a[1]-a[0]*2)].max
  return
end

if a.length.odd?
  a = a.sort!.each_slice(a.length / 2 + 1).to_a
else
  a = a.sort!.each_slice(a.length / 2).to_a
end

p 0

