query: How many iterations of the DS have been released?
passage: Nintendo DS family
Throughout its lifetime, Sony's PlayStation Portable has been the main market competitor. There have been four different models of the Nintendo DS line on the market: the original Nintendo DS, the Nintendo DS Lite, as well as the Nintendo DSi and its XL variant. The Nintendo DS line has been highly successful, continuing the trend of its predecessor, the Game Boy line. With over 154 million units sold worldwide, the DS models are the best-selling handheld consoles, and second best-selling console overall behind the PlayStation 2.
passage: Citroën DS
After 18 years of secret development as the successor to the Traction Avant, the "DS 19" was introduced on 5 October 1955 at the Paris Motor Show. In the first 15 minutes of the show, 743 orders were taken, and orders for the first day totalled 12,000. During the 10 days of the show, the DS took in 80,000 deposits; a record that stood for over 60 years, until it was eclipsed by the Tesla Model 3 which received 180,000 first day deposits in March 2016.