Solve fast

I need urgent

A brick of mass 1kg travels to the right at 0.8c, where c is the speed of light. It collides with another brick of mass 2kg which is at rest before the collision. After the collision, the lighter brick has a speed of 0.67c, still to the right.

What is the momentum of the heavier brick after the collision? Keep three significant digits.

(Hint: be careful to use the relativistic expressions for momentum)