London was the first city to host the Summer Olympic Games three times. As of 2022, Paris, Los Angeles, Athens and Tokyo have each hosted twice; Paris will host for the third time in 2024, followed by Los Angeles which will host the Games in 2028. Only five countries have participated in every Summer Olympic Games: Australia, France, Great Britain, Greece, and Switzerland. Australia, France and Great Britain have won at least a medal at every edition of the Games, with Great Britain as the only one to win gold each time. The United States leads the all-time medal count at the Summer Olympics, and has topped the medal table on 18 separate occasions—followed by the USSR (six times), and France, Great Britain, Germany, China, and the ex-Soviet 'Unified Team' (once each).
Extract all the place names from the paragraph. Different places should be separated by comma.
Paris, Los Angeles, Athens, Tokyo, Australia, France, Great Britain, Greece, Switzerland, Australia, France, Great Britain, USSR,Germany, China