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.

Positive Example 1 -
Input: fear of needles (medically known as belomophobia) is a term used to describe a large fear (phobia) of medical procedures involving needles.
Output: fear of needles

Positive Example 2 -
Input: the 2015 ping an chinese football association super league (chinese: 2015中国平安中国足球协会超级联赛) was the 12th chinese super league season and was won by guangzhou evergrande taobao.
Output: 2015 chinese super league

Negative Example 1 -
Input: roaring lion (march 11, 2015 – august 23, 2019) was an american-bred, british-trained thoroughbred racehorse.
Output: roaring racehorse

Negative Example 2 -
Input: the maillard reaction is a chemical reaction between an amino acid and a reducing sugar that gives browned food its distinctive flavor.
Output: chemical reaction

Now complete the following example -
Input: the international date line (idl), also known as just the date line, is an imaginary line on the surface of the earth, going from north to south in the pacific ocean.
Output: 


Output: international date line