Summer Olympic Games demand for tickets to all levels of each event, there was controversy when seats set aside for sponsors and National Delegations went unused in the early days. A system of reallocation was put in place so the empty seats were filled throughout the Games. Rio de Janeiro, Brazil hosted the 2016 Summer Olympics, becoming the third city in the Southern Hemisphere to host the Olympic Games after Melbourne, Australia, in 1956 and Sydney, Australia, in 2000, and the first South American city to host the Olympics. The preparation for these Games was overshadowed by controversies, including the instability of Brazil's
Olympic Games ceremony I declare open the Rio Olympic Games, celebrating the XXXI Olympiad of the Modern Era". Next, the Olympic flag is carried horizontally (since the 1960 Summer Olympics) into the stadium and hoisted as the Olympic Hymn is played. The Olympic Charter states that the Olympic flag must "fly for the entire duration of the Olympic Games from a flagpole placed in a prominent position in the main stadium". At most games, the flag has been carried into the stadium by prominent athletes of the host nation, but in 2012, it was carried by an international group of athletes and non-athletes