As an exercise, I wrote a quick and dirty python script to solve this back in February (albeit it's not the most elegant solution but far better than brute force) and submitted my answer and subsequent contact info hoping to eventually hear back about said interview, and never did.
Which is quite frustrating from the perspective of someone on the job hunt. Why use something like this as a hiring tool and not follow up on it?
Let's stop and think. This is a good thing.
The truth is, none of us know whether or not it's snake oil. Just because we don't have enough information to prove it isn't a farce (besides the founders' insistence on their good health), does not mean we have enough information to prove that it is.
Is it dangerous? Highly unlikely. The vast majority of early adopters will probably be people at least somewhat characteristic of this community, meaning smart enough to know that if something makes you feel awful, you should probably stop eating it. If you bought a month's supply, maybe you get burned a few hundred bucks and it wasn't the best decision. If you bought a week's supply, you tried it for a few days and felt terrible, just make the intelligent decision and stop eating it (or drinking or whatever the process of consumption should be called).
Whether or not the people behind this are looking out for everyone else, we don't know. But let's be honest, neither is McDonald's or even the businesses stocking microwave dinners in grocery stores. They're in it to make a profit, not to fill you with the proper nutrition. Frankly, the goal of many of the businesses in the food industry is to cause customers to crave the product, often at the expense of nutrition (i.e. by loading with sugar, conditioning the brain to crave more). To say that they know better than these 20-somethings who have been collecting some actual data besides "hm, tastes good" is exceptionally naive. Your average gym rat eats far healthier than a microwave dinner diet.
This could be bad. But none of us have the data to prove it. Until then, I'm hopeful. Innovation in this industry is long overdue.
To say that these 'kids' are too young or inexperienced to make a real innovation and prove us all wrong, is a shame, especially in this community.
Is it perfect for everyone? Doubtful.
Is it better, on average, than the diet many of us are consuming? Well, that just might be true.
Who are we to say it isn't?
So the 4 letters descending from the column marked (LN|K|D)* should match the regex ^.(LN|K|D)*$ entirely. Hope that helps.