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: 'the baby giraffe is stretching its neck to look at mama'. Reverse all words of length '2' in the given sentence.

the baby giraffe si stretching its neck ot look ta mama