Definition: 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.
Input: Sentence: 'a crowd of children watch two cakes which are sitting on a table while an adult is holding a knife over them'. Reverse all words of length '5' in the given sentence.

a dworc of children hctaw two sekac hcihw are sitting on a elbat elihw an tluda is holding a efink over them