require 'bigdecimal'

class Yukicoder
  def initialize
    n = gets.chomp.to_i

    sum = BigDecimal('0.0')

    n.times do
      sum += BigDecimal(gets.chomp)
    end

    f, x, y, z = sum.split
    x.insert(z,'.')
    x += '0'
    x = x.split('.')
    puts x.first + '.' + x.last[0..9].ljust(10, '0')
  end
end

Yukicoder.new