Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: The Trans-Pacific Partnership (TPP) is one of the most ambitious free trade agreements ever signed. It involves 12 countries with a collective population of 800 million.

TPP: How social media reacted