In which among the following flats minimum persons live?** Twelve persons live in a five-floor building such that the bottommost floor is numbered as ...

In which among the following flats minimum persons live?**

Twelve persons live in a five-floor building such that the bottommost floor is numbered as 1, the floor just above it is numbered as 2 and so on till the topmost floor is numbered as 5. Each floor has four flats – J, K, L and M from west to east respectively. Flat K is to the east of flat J and to the west of flat L which is to the west of flat M. 8 flats are vacant.

Note:

1. At least two but not more than three persons live on each floor. The adjacent flats are not vacant. Adjacent flats are immediate left, immediate right, immediately above and immediately below.
2. If it is given that A lives immediately above/immediately below B's flat then either a vacant flat is between A and B or there is no vacant flat (no floor) between A and B.

W lives to the east of U but neither in flat K nor in flat M. Only one floor gap is between W and P who lives to the west of S but not just west. U and P live in different named flats. R lives above S and adjacent to one of the vacant flats. R and W live in different named flats. O lives to the west of R and east of V. Q lives immediately below O's flat. T lives to the east of Q. Only one floor gap between T and Y. T lives immediately above Y's flat. Z lives just northwest of X.