TASK DEFINITION: Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.
PROBLEM: "polythene pam" is a song written by john lennon, credited to lennon/mccartney, and performed by the beatles on their album "abbey road".

SOLUTION: polythene pam

PROBLEM: carl-henning pedersen (23 september 1913 – 20 february 2007) was a danish painter and a key member of the cobra movement which existed from 1948 to 1951.

SOLUTION: carl-henning pedersen

PROBLEM: the union army was the name of the army that fought for the union during the american civil war.

SOLUTION:
union army