In this task, you are given a sentence. You must find the primary subject in the supplied sentence. The output must be a sub-sequence in the sentence.

Ex Input:
All three should be spread about one-third of the boat's length apart.

Ex Output:
All three

Ex Input:
It should therefore be examined frequently for signs of deterioration.

Ex Output:
It

Ex Input:
Handling of man-made fibre cordage.

Ex Output:
man-made fibre cordage