Definition: 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).

Positive Example 1 -
Input: Mr. Miller waved his hands in a gesture of divine despair, spun round, darted up the aisle, turned, and bounded back.
Output: Mr. Miller, hands

Positive Example 2 -
Input: She snatched the photograph away, cast one glance at the languishing brown eyes, and tumbled it, face downward, into a bureau drawer.
Output: She, the photograph

Negative Example 1 -
Input: The God of Luck had smiled upon his boldness, and, reflecting upon it Kan Wong turned back to the river and the sampan that had so long been his floating home.
Output: The God of Luck

Negative Example 2 -
Input: The Wolf was dead, and I hallooed to Snap, but he did not move.
Output: The Wolf

Now complete the following example -
Input: A man is water skiing behind a boat on a lake.
Output: 


Output: man, boat