Um, 'scuse me but Gene posted that, and it is a very sensible issue of who is going to handle the day-to-day business. I'm waiting to see if Igor tells us how many units in total are in the complex, to get some idea of the economies of scale, and whether or not the other owner(s) have a fix (like a resident manager).
The original question concerns who, exactly, owns what, and who is responsible for which maintenance, insurance, etc., such as the shared stairway (cleaning, painting). The recorder of deeds (intenet access) probably has the property description in some detail, but probably not a copy of any agreements as to standards. The insurance probably gives some specificity, but the other owner(s) would be an essential contact (residents should have the phone number for you as well as valuable info about the conditions and management).