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 strands are twisted up together to form the rope, and
Example Output: the strands

Example Input: The rope is flexible, durable, strong, and stands up well to wear and weather.
Example Output: The rope

Example Input: One must learn to interpret these characteristics.
Example Output:
these characteristics