Here is the problem: Primary U.S. interstate highways are numbered 1-99. Odd numbers (like the 5 or 95) go north/south, and evens (like the 10 or 90) go east/west. Auxiliary highways are numbered 100-999, and service the primary highway indicated by the rightmost two digits. Thus, the 405 services the 5, and the 290 services the 90.

Given a highway number, indicate whether it is a primary or auxiliary highway. If auxiliary, indicate what primary highway it serves. Also indicate if the (primary) highway runs north/south or east/west.

Ex: If the input is:

90

the output is:

The 90 is primary, going east/west.

Ex: If the input is:

290

the output is:

The 290 is auxiliary, serving the 90, going east/west.

Ex: If the input is:

0

or any number not between 1 and 999, the output is:

0 is not a valid interstate highway number.

How do I solve this problem?