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.

Input: Consider Input: doriva (born 28 may 1972) is a former brazilian football player.

Output: doriva


Input: Consider Input: molar mass is the mass of a substance that has 6.022 × 10 atoms (avogadro's number).

Output: molar mass


Input: Consider Input: supreme commander is a real-time strategy computer game.


Output: supreme commander