A pilot steers his helicopter at night over Rio de Janeiro, Brazil, less than two weeks before the start of the Rio 2016 Olympic Games, July 23, 2016. Picture taken July 23, 2016. (Photo by Pawel Kopczynski/Reuters)

A pilot inflates a hot air balloon while taking part in the 38th International Balloon Festival of Chateau-d'oex, Switzerland, 23 January 2016. The festival takes place from 23 to 31 January. (Photo by Vincent Vannay/EPA)

A woman aims a World War II machine gun at a military show during celebration of the Defenders of the Fatherland Day in St.Petersburg, Russia, Tuesday, February 23, 2016. The day, celebrated in Russia on February 23, honors the nation's military and is a nationwide holiday. (Photo by Dmitri Lovetsky/AP Photo)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

Festival goers arrive for the Glastonbury festival at Worthy Farm, in Somerset, England, Thursday, June 23, 2016. (Photo by Guy Bell/Rex Features/Shutterstock)

People are caught in a dust storm in New Delhi, India May 23, 2016. (Photo by Anindito Mukherjee/Reuters)

A woman paints the floor of a pond as her child pulls at her saree in Delhi, India November 23, 2016. (Photo by Cathal McNaughton/Reuters)

A worker applies colour to strings which will be used to fly kites, by a roadside in Ahmedabad, India, November 23, 2017. (Photo by Amit Dave/Reuters)