Assistance with "go to" link (Harlowe 3.3.1)

Hello! I have a passage where the player has to solve a riddle. The answer is “13.” I want them to be able to type the answer into a prompt box and then, if they typed the right answer, go to one section and if they typed the wrong answer, go to a trap section. I’m struggling to get the code to work. Right now, it always sends them to the trap section, no matter what they type in.

(set: $riddle to (prompt: [You set the dial to...], "TYPE NUMBER HERE"))
(if: $riddle is 13)[(go-to: "(13) right Answer)"]
(else:)[(go-to: "Jill Sandwich!")]

After some experimentation, I actually think I got it!

(set: $riddle to (prompt: [You set the dial to...], "TYPE NUMBER HERE"))
(if: $riddle is '13')[(go-to: '(13) right Answer')]
(else:)[(go-to: 'Jill Sandwich!')]

Of course, if others have other ways they did it, let me know! Happy to compare.