In this task, you are given a sentence which contains a motion and your task is to identify the physical entities involved in the motion. The input sentence can have more than one entity and also there is at least one entity that takes part in physical motion. There are two types of entities which are animate (beings that are alive) and inanimate entities (beings that are not alive).

Example Input: A set of instructions are shown transitioning back and fourth between a man laying down carpet on a set of stairs.
Example Output: man

Example Input: He then opened the office door and ascended the staircase.
Example Output: He

Example Input: "There's always a modus vivendi," Penfentenyou murmured, and tiptoed along the hall to a back door, which he opened quite silently.
Example Output:
he