inputs = STDIN.readlines.map(&:chomp)
n = inputs[0].to_i
as = inputs[1].split(/\s+/).map(&:to_i)

def median(n, as)
  sorted = as.sort
  if n % 2 == 0
    (sorted[n / 2 - 1] + sorted[n / 2]) / 2.0
  else
    sorted[(n - 1) / 2]
  end
end

puts "%.1f" % median(n, as)