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.

Example Input: The number and size of the yarns required to make each strand depends on the size of the rope it is intended to make.
Example Output: the yarns

Example Input: Furthermore, cable-laid rope, being more solid in construction, is more resistant to chafe and does not absorb water so readily as hawser-laid rope.
Example Output: cable-laid rope

Example Input: This process is called 'laying' and is always carried out in the opposite direction to that used in the previous stage of twisting the strands; it is, moreover, distinct from the simple spin or twist and is twofold, in that:
Example Output:
This process