I'm trying to complete the Hands-on Challenge for Manage Your Picklist Values, and I'm getting the following message "... Couldn’t find picklist formula with the correct information. Please double check the instructions" I used the formula provided:

Use the formula editor to set the Default Value for the Macaron Flavor picklist as follows:CASE(MONTH(TODAY()),1, "Gingerbread",2, "Strawberry",4, "Chocolate",7, "Raspberry",11, "Pumpkin",12, "Mint", "Vanilla")

These were the only instructions, 

As an administrator, you want the default value for the macaron flavor to be the flavor of the month for some months, otherwise, the default is vanilla.

I'm not quite sure what I'm doing wrong.