You will be given a definition of a task first, then some input of the task.
In this task, you need to reverse all words of a given length in the sentence. The number of letters in a word determine its length. For example, the length of the word "apple" is 5.

Sentence: 'a group of chefs gathering around a table preparing meals'. Reverse all words of length '5' in the given sentence.
Output:
a puorg of sfehc gathering around a elbat preparing slaem