Currently there are 27 native Standard Prime lenses for Panasonic S5 II and 25 of these lenses are autofocus (AF) type.
S5 Mark II also has a sensor based image stabilization system which means that all of these lenses will be stabilized when used on S5 Mark II.
Since Panasonic S5 II has environmental sealings (Weather Sealing), you may like to couple your camera with one of these 16 Standard Prime lenses with Weather Sealings.