Help needed finding lateral magnification?!?

A simple camera telephoto lens consists of two lenses. The objective lens has a focal length f1 = +40.4 cm. Precisely 34.0 cm behind this lens is a concave lens with a focal length f2 = -14.0 cm. The object to be photographed is 3.84 m in front of the objective lens.The film can be placed 54.8 cm behind the concave lens. What is the lateral magnification of this lens combination?