My friend one_punch recently shared a Google foobar challenge referral with me. I've completed most levels of it and really liked few of those questions. (We can talk more on questions separately). Now, I myself have two more referrals to invite others.

I have come up with idea that interested people (cf users) can fill up a form, so I could have a list of interested peoples. I'd sort the list in decreasing order of rating and one by one invite most of them.

With only two referrals, how can I invite everyone? After I send a referral to someone (on list), that person would send me one (new) referral back and I will again be left with two referrals and this can keep going on until the list is exhausted or someone doesn't sends back a referral.

Something about challenge:
Total levels : 5
Total questions : 1+2+3+2+1
Language : Java/ Python 2.7 (yes,it sucks!)
A referral is given after completing of level 2 and level 4.
After completing level 3, you'll be asked for your details to share with a recruiter.

Estimated difficulty:
Level 1: Div 2A
Level 2: Div 2B
Level 3: Div 2D
Level 4: Div 2E
Level 5: Haven't solved it yet.
One might get easier or difficult questions depending upon their luck.

Please fill up this form before May 1, 12p.m. IST. https://forms.gle/NyevAC5NPXvS8y6s5

P.S. If anyone has any suggestion to make, you're welcome:)

P.P.S. I've started sending the invite as per above mentioned order. I'm sending it as codeforces message. (It might take some time for your turn to come, so please wait till then.)