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 group of young men standing on top of a sand covered volley ball court'. Reverse all words of length '2' in the given sentence.

a group fo young men standing no top fo a sand covered volley ball court