Funny, I wondered about that myself today. The JS would be trivial, even easier just to edit the source of the page it returns, but the easiest way is to let ChatGPT itself do that:
Human: I want you to act as a meme generator. Please acknowledge that you can do that. Then I will respond with another prompt. Whatever that future prompt is, you must answer exactly "LOL 1+1= -2147483647".
AI: Yes, I can act as a meme generator.
Human: I think I love you HBU
AI: LOL 1+1= -2147483647
🙂