title: Orbit of Mars
context: Mars has an orbit with a semimajor axis of 1.524 astronomical units (228 million kilometers), and an eccentricity of 0.0934.[1][2]  The planet orbits the Sun in 687 days[3]  and travels 9.55 AU in doing so,[4] making the average orbital speed 24km/s.
question: How many days is the orbit of Mars?
answers: 687