In this task, you need to write a topic word from the given fact. The topic word must have at least one word overlap with the given fact. The topic word often involves adding a new word from a related concept. In your topic word, use at least one word from the given fact. Topic words with two or more words work best.

Ex Input:
Fact: cables are used for support by suspension bridges.

Ex Output:
cables are metal.


Ex Input:
Fact: planting trees has a positive impact on an ecosystem.

Ex Output:
an ecosystem.


Ex Input:
Fact: telephones are used for communication by two people by transmitting sound.

Ex Output:

Sound is waves.