class Findmedian
    attr_reader :n, :a

    def initialize(n: 0, a: [])
        @n, @a = n, a
    end

    def datainput
        begin
            @n = Integer(gets.chomp)
            @a = gets.chomp.split.map { |v| Integer(v) }
        rescue
            
        end
    end

    def findmedian(n, array)
        array = array.sort
        if n % 2 == 0
            v = array[(n / 2)-1] + array[n / 2]
            (v % 2 == 0)? v / 2 : v / 2.to_f
        else
            array[(n / 2).floor]
        end
    end

    def dataoutput
        puts findmedian(@n, @a)
    end

    def run
        datainput
        dataoutput
    end
end

if $0 == __FILE__
    Findmedian.new.run
end