num = gets.to_i

num_array = []
num_array = gets.split.map(&:to_i)

num_array.sort!

if num_array.length.odd?
	puts num_array[num_array.length - 2]
else
	puts (num_array[num_array.length/2] + num_array[num_array.length/2 - 1]) / 2.0
end