Non-responsive to gas pedal. on 1998 Mercedes-Benz SL600

I don't drive my car much. It has 13,000 miles. When I tried to start it this Spring, the battery was dead and needed to be jumped. When it started, it ran rough and the engine is not responding to the gas pedal. It just idles rough at the same speed.

Asked by for the 1998 Mercedes-Benz SL600