In this task, you will be presented with a question and you have to answer the question based on your knowledge. Your answers should be as short as possible.

Example input: Who were the builders of the mosque in Herat with fire temples ?
Example output: Ghurids
Example explanation: This is a good example. Ghurids were the builders of the mosque in Herat with fire temples.
Q: How long is this river that was the venue for the Summer Olympic officially known as the Games of the II Olympiad ?
A:
777-kilometre-long