def report$\_$size$($n: int$)->$ str:

$"""$Return 'small' if n is between $0$ and $20$ inclusive,

'medium' if n is between $21$ and $40$ inclusive,

and 'large' if n is $41$ or greater.

Precondition: n $>=0$

$>>>$ report$\_$size$(4)$

'small'

$>>>$ report$\_$size$(24)$

'medium'

$>>>$ report$\_$size$(45)$

'large'

$"""$