The current order in process can have at most $3$ alcoholic beverages.

The minimum age to order alcohol drink is $21$

Start please a new order:

Your Total Order for now is $0\mathrm{.}0$

Would you please enter your name John

Would you please enter your age $23$

Your age is above $20$ and you are eligible to order alcohol

Would you please add an alcohol drink

The current order of drinks is $1$

The Total price on the Order is $2\mathrm{.}0$

Your current alcohol drink order is less than $4$

Would you please add a second alcohol drink

The current order of drinks is $2$

The Total Price on the Order: $6\mathrm{.}0$

Your current alcohol drink order is less than $4$

Add third alcohol drink

The current order of drinks is $3$

The Total Price on the Order: $8\mathrm{.}0$

You have a maximum alcohol drinks for this order

Would you please add a COFFEE to your order:

Total items on your order is $4$

The Total Price on the Order: $11\mathrm{.}0$