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: 'a river filled with lots of boats and surrounded by buildings'. Reverse all words of length '4' in the given sentence.
Example Output: a river filled htiw stol of boats and surrounded by buildings

Example Input: Sentence: 'a motorcycle parked on the street and next to parked cars'. Reverse all words of length '1' in the given sentence.
Example Output: a motorcycle parked on the street and next to parked cars

Example Input: Sentence: 'many people with skis go up a mountain'. Reverse all words of length '6' in the given sentence.
Example Output:
many elpoep with skis go up a mountain