How many persons live between E and F?

Study the following information carefully and answer the question given below: There are eight people Y, Z, M, N, A, B, E and F are living in a 8 floor Building on different floors from top to bottom (such as ground floor is numbered as 1 and top floor is numbered as 8) but not necessarily in the same order. No two persons according to alphabetical order live adjacent to each other(Y does not live just above or below Z, Z does not live just above or below Y and M, and so on). N live either 2nd or 7th floor. Only two persons live between M and
B. A lives immediately below
M. E live above B but not at the topmost floor. Only one person sit between Z and
B. M live on 6th floor.