The orbit of halleys comet around the sun is a long thin

Question

Question: The orbit of Halley's Comet around the Sun is a long thin ellipse. At its aphelion (point farthest from the Sun), the comet is 5.33× 10¹² m from the Sun and moves with a speed of 11.5 km/s.

Part A: What is the comet's speed at its perihelion (closest approach to the Sun) where its distance from the Sun is 8.58×10¹⁰ m?

I need help to find the comet's speed at its perihelion.