I am currently preparing for ZIO. While I was going through some past papers I came across a problem from ZIO 2014(Q.3) It contains a keypad(3*3 grid) with numbers 1 to 9. I have the first number and the total no. of digits. I need to find the number of possible keycodes. Note: we can only move to a number adjacent to the number we have currently typed in.

Subproblems:

I) first digit 2, total digit 8

II) FD 5, TD 10

III) FD 9, TD 13