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.

Example Input: teleportation is the supposed movement of matter from one point to another without travelling across the physical space between them.
Example Output: teleportation

Example Input: someo is a village and former municipality of the district of vallemaggia in the canton of ticino in switzerland.
Example Output: someo

Example Input: attack on titan: lost girls (進撃の巨人 lost girls, shingeki no kyojin: lost girls) is a japanese novel written by hiroshi seko.
Example Output:
attack on titan: lost girls