(Each shelf, with at least two slots, with a dotted slot denoting potential extra/s.) The bottom shelf has 3 because we know that if it has more than the top, and the top has at least two, the bottom has at least 3.
I would then place I, which it tells us is always on the middle shelf.
I draw vertical games vertically because that's how my brain works - they say top/bottom, I look at the top/bottom. Some people find this disorienting if they only like to do horizontal set ups, so use what works best for you.