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: 'two doubledecker buses are parked at a bus stop next to some buildings with another doubledecker bus on the road going the other direction behind them'. Reverse all words of length '1' in the given sentence.

two doubledecker buses are parked at a bus stop next to some buildings with another doubledecker bus on the road going the other direction behind them