Ranking

Eight floors in a building (from 1 to 8) are occupied by A, B, C, D, E, F, G and H, with each person occupying a distinct floor. Further it is known that:

• A lives 5 floors above B.
• H lives on the only floor between C and E.
• D and F live on adjacent floors.
• B does not live on the 1st floor.
  ‘N’ is defined as the difference between the floor numbers of C and D. How many different values of ‘N’ are possible?