A child rescued from Boko Haram in Sambisa forest is seen at the Internally Displaced People's camp in Yola, Nigeria May 3, 2015. Hundreds of traumatised Nigerian women and children rescued from Boko Haram Islamists have been released into the care of authorities at a refugee camp in the eastern town of Yola, an army spokesman said. (Photo by Afolabi Sotunde/Reuters)

Revelers dance and shout as they listen to music, in front of the main stage, during the 21st Woodstock Festival in Kostrzyn-upon-Odra, Poland July 31, 2015. An estimated 200,000 people attended the ongoing festival, a brainchild of Polish journalist and social campaigner Jerzy Owsiak, on Friday. Owsiak initiated the event to say thank you to those who donated money to his GOCC charity organisation that delivers medical care for children. (Photo by Kacper Pempel/Reuters)

Cheerleaders wait to perform before the New Year's Day parade in London, Britain January 1, 2017. (Photo by Neil Hall/Reuters)

A participant has his body painted before a regional bodybuilding championship in Stavropol, southern Russia, April 10, 2016. (Photo by Eduard Korniyenko/Reuters)

Japanese team trains before the 6th FINA Synchronised Swimming World Trophy at the Water Cube on December 8, 2011 in Beijing, China. (Photo by Feng Li/Getty Images)

Greyhounds with stuffed and sprung model monkeys strapped to their backs before a hurdle race at Wellinborough. (Photo by E. Bacon). 21st April 1928

Participants in costumes pose before a Halloween parade in Kawasaki, south of Tokyo, Japan on October 28, 2018. (Photo by Toru Hanai/Reuters)