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 Q]: A coir rope is the weakest of all cordage, but it has the advantage of being so light that it floats on water.
[EX A]: A coir rope

[EX Q]: The quality varies greatly with the soil in which it is grown, and for purposes of Admiralty specification it is graded for quality in the order Italian, European, New Zealand and St.
[EX A]: it

[EX Q]: The quality of the finished rope depends upon the thorough cleaning of the fibre during this stripping process.
[EX A]:
the finished rope