$4\mathrm{.}25$ LAB: Countdown until matching digits

Write a program that takes in an integer in the range $11-100$ as input. The output is a countdown starting from the integer, and stopping when both output digits are identical.

Ex: If the input is:

$93$

the output is:

$93$

$92$

$91$

$90$

$89$

$88$

Ex: If the input is:

$11$

the output is:

$11$

Ex: If the input is:

$9$

or any value not between $11$ and $100($inclusive$),$ the output is:

Input must be $11-100$