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.

Sentence: 'a bear rolling on his back on some logs'. Remove all words of length '2' in the given sentence.
a bear rolling his back some logs

Sentence: 'a european army helicopter flying in the sky'. Remove all words of length '8' in the given sentence.
a army helicopter flying in the sky

Sentence: 'a clock tower lit up at night time in a city'. Remove all words of length '3' in the given sentence.

a clock tower up at night time in a city