kiekrz

require 'nokogiri'
require 'open-uri'
require 'net/http'
require 'prime'

url = "http://5.9.247.121/d34dc0d3"
uri = URI.parse(url)

kek = Nokogiri::HTML(open(url, "X-0x0ACE-Key" => "jq1Og5wWzvkqlMRjeDQdyrAOLZ2oJBoYwEXnxa6VwYPb0p1ENG5g894KmRzQyZ8W" ))
str = kek.css(".challenge").first.content.lstrip
verification_code = kek.css("form > input[name=verification]").first.attributes["value"].value

arr = str.scan(/\d+/)
range = (arr.first.to_i .. arr.last.to_i).to_a[1..-2]
primes = range.select { |i| Prime.prime?(i) }
primelist = primes.join(",")

req = Net::HTTP::Post.new(uri.path)
req.set_form_data({'verification' => verification_code, 'solution' => primelist})
req["X-0x0ACE-Key"] = "jq1Og5wWzvkqlMRjeDQdyrAOLZ2oJBoYwEXnxa6VwYPb0p1ENG5g894KmRzQyZ8W"

res = Net::HTTP.start(uri.hostname, uri.port) do |http|
  http.request(req)
end

puts res.body