Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

Rebels of the Revolutionary Armed Forces of Colombia (FARC) visit as they wait to have lunch in El Diamante, Colombia, Friday, September 16, 2016. FARC rebels are gathering for a congress were delegates will debate and vote on the accord reached last month with the Colombian government to end five decades of war. (Photo by Ricardo Mazalan/AP Photo)

A miner with a donkey makes his way through the low and narrow tunnel leading out of a coal mine in Choa Saidan Shah in Punjab province, April 29, 2014. Workers at this mine in Choa Saidan Shah dig coal with pick axes, break it up and load it onto donkeys to be transported to the surface. Employed by private contractors, a team of four workers can dig about a ton of coal a day, for which they earn around $10 to be split between them. The coalmine is in the heart of Punjab, Pakistan's most populous and richest province, but the labourers mostly come from the poorer neighbouring region of Khyber Pakhtunkhwa. (Photo by Sara Farid/Reuters)

Pope Francis passes past a portrait of himself as he arrives to meet youths in Santo Tomas University in Manila, Philippines, Sunday, January 18, 2015. Francis is in the Philippines on Sunday, the final full day of a weeklong trip that also took him to Sri Lanka. (Photo by Alessandra Tarantino/AP Photo)

Children displaced as a result of Boko Haram attacks in the northeast region of Nigeria, run at a camp for internally displaced persons (IDP) in Yola, Adamawa State January 13, 2015. Boko Haram says it is building an Islamic state that will revive the glory days of northern Nigeria's medieval Muslim empires, but for those in its territory life is a litany of killings, kidnappings, hunger and economic collapse. (Photo by Afolabi Sotunde/Reuters)

Fans of Germany react as they watch the Euro 2016 match between France and Germany in France at a public screening of the match in Berlin, Germany, July 7, 2016. France won 2-0. (Photo by Hannibal Hanschke/Reuters)

Festival goer practice yoga during the O.Z.O.R.A. festival on August 4, 2016 in Tolna, Hungary. Ozora is a village in Tolna County. In recent times it has become famous for the O.Z.O.R.A. psychedelic trance festival which has been held on an estate in Ozora near small village Dadpuszta every year since 2004. The first party was called Solipse and took place during the Solar eclipse of August 11, 1999. (Photo by Mohai Balázs/MTI/MTVA)

Principle Ballet Dancer, Ekaterina Bulgutova, of the Russian State Ballet, with the Nutcracker part of Christmas Ballet Season in Cardiff which starts at St Davids Hall on December 20, 2016 in Cardiff, England. (Photo by Kiran Ridley/Barcroft Images)