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.

Example Input: Sentence: 'an elderly man in a jacket is walking outside of a window'. Reverse all words of length '3' in the given sentence.
Example Output: an elderly nam in a jacket is walking outside of a window

Example Input: Sentence: 'a group of snow boarders pose in the snow on top of a hill'. Reverse all words of length '5' in the given sentence.
Example Output: a puorg of snow boarders pose in the snow on top of a hill

Example Input: Sentence: 'a blie bag is sitting on a desk'. Reverse all words of length '2' in the given sentence.
Example Output:
a blie bag si sitting no a desk