Definition: In this task, you need to remove 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: 'an airplane with the word navy pained on the side is sitting on a runway and people are sitting inside of the plane'. Remove all words of length '3' in the given sentence.

an airplane with word navy pained on side is sitting on a runway people sitting inside of plane