input = gets(nil).chomp

def seq(a)
  s = []
  1.upto(10) do |i|
    if i == 1
      s[0] = a
      next
    end

    if i % 2 == 0
      s[i-1] = s[i-2]*2
    else
      s[i-1] = s[i-2]/3
    end
  end
  s.inject(:+)
end

input.split("\n").each do |line|
  a = line.to_f
  puts seq(a)
end