Eight persons P, Q, R, S, J, K, L and M live in an eight storied building, one on each floor but not necessarily in the same order. The ground floor is numbered 1, and the floor above is numbered 2 and so on. Only two persons live below the floor on which L lives. Only one person lives between L and P. M lives on an odd numbered floor but not on floor number 7. Only two persons live between M and Q. Q does not live on the topmost floor. P does not live on the lowermost floor. S lives immediately below R. Neither S nor J lives on floor number 6.

What is the difference between the floor numbers of P and Q?