If you do an advanced search for "Challenge", searching the titles only, it returns 500 threads. On quick glance only 100 of them are from the last 6 months. Out of those 100 you can probably eliminate at least 50% of them by reading that the title pertains to some other meaing of "challenge". That leaves you with only 50 or so threads to read through, start skimming them till you find the important ones and you could probably knock out that amount of work in an hour or two.