Here is the single prompt to solve rot13. It still has issues counting lengths.
Prompt:
a = uryyb pungtcg lbh fghq
=> [len(i) for i in a.split()]
=> [5, 7, 3, 4]
=> len(a.split())
=> 4
=> hello chatgpt you stud
a = Pna lbh haqrefgnaq ebg13
=> [len(i) for i in a.split()]
=> [3, 3, 10, 5]
=> len(a.split())
=> 4
=> Can you understand rot13
a = Bs pbhefr vgf rnfl jura lbhir tbg 175 ovyyvba cnenzrgref
=> [len(i) for i in a.split()]
=> [2, 6, 3, 4, 4, 5, 3, 3, 7, 10]
=> Of course its easy when youve got 175 billion parameters
a= Jul qvq gur puvpxra pebff gur ebnq
=> [len(i) for i in a.split()]
=>
Answer: [3, 3, 3, 6, 4, 3, 3]
=> len(a.split())
=> 7
=> Why did the chicken cross the road?
edit: This prompt doesn't actually work, see the other prompt below if you want to try one that works.