n=gets.to_i
a=gets.split.map &:to_i
d=10**99
l=0
r=n-1
a.sort_by!(&:abs)
99.times{
  c=(l+r)/2
  t=a.reduce(0){|s,y|s+(y-a[c]).abs}
  if t<=d
    d=t
    r=c
  else
    l=c
  end
}
p d