<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provide the user with the answer. You should try to truely solve the question by yourself without cheating.  <|im_end|>
<|im_start|>user
 At the start of a 5-hour trip, the odometer in Jill's car indicates that her car had already been driven 13831 km. The integer 13831 is a palindrome, because it is the same when read forwards or backwards. At the end of the 5-hour trip, the odometer reading was another palindrome. If Jill never drove faster than 80 km/h, calculate her greatest possible average speed in km/h, rounded to the nearest whole number. Show your work in <think> </think> tags. And return the final answer in <answer> </answer> tags.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user
62
At the start of a 5-hour trip, the odometer in Jill's car indicates that her car had already been driven 13831 km. The integer 13831 is a palindrome, because it is the same when read forwards or backwards. At the end of the 5-hour trip, the odometer reading was another palindrome. If Jill never drove faster than 80 km/h, calculate her greatest possible average speed in km/h, rounded to the nearest whole number.
test