A picture made available on 09 October 2016 shows competitors during a Legion Run event, in Sofiko near the city of Corinth, Greece, 08 October 2016. Legion Run is run covering five kilometres with obstacles of mud, fire, ice and barbed wire, which takes place in different countries around the globe. (Photo by Vassilis Psomas/EPA)

A Ukrainian serviceman fires a 2S7 Pion self-propelled gun during military exercises near the village of Divychky in Kiev region, Ukraine, October 21, 2016. (Photo by Valentyn Ogirenko/Reuters)

A military guard carries flowers through the Cementerio Santa Ifigenia where the remains of former Cuban President Fidel Castro were entombed December 4, 2016 in Santiago de Cuba, Cuba. The tomb stands to the side of a memorial to the rebel soldiers killed in an attack that Castro led on Santiago's Moncada barracks on July 26, 1953, and in front of the mausoleum of Cuban national hero Jose Marti. (Photo by Chip Somodevilla/Getty Images)

Members of the Indonesian Presidential Security Forces (Paspampres) show their skills during the simulation of a terrorist attack in Jakarta, Indonesia, 29 December 2016. According to reports in local media the Indonesian security forces have already arrested 21 terrorists suspects and fatally shot five of them, who were allegedly planning attacks in the Indonesian capital during the Christmas and New Year's Eve celebrations this year. The presentation was shown on the occasion of a visit by Indonesian President Joko Widodo and a delegation to the Paspampres headquarters in Jakarta. (Photo by Bagus Indahono/EPA)

A man rides a horse at a playground on a hill in Kabul April 19, 2015. (Photo by Mohammad Ismail/Reuters)

A Balinese Hindu blows fire, during a parade carrying Ogoh-ogoh effigies symbolising evil spirits, during a ritual before Nyepi, the day of silence, in Palembang, South Sumatra province, Indonesia March 8, 2016. Nyepi is a day of silence for self-reflection celebrating the Balinese Hindu new year, where people may not use lights, light fires, work, travel nor enjoy entertainment. (Photo by Darren Whiteside/Reuters)

A boy looks inside the skull of a Tyrannosaurus Rex replica at the Egidio Feruglio Museum in Trelew, Argentina, in this May 18, 2014 file photograph. Scientists on July 28, 2015 unveiled a comprehensive analysis of the teeth of the group of carnivorous dinosaurs called theropods, which include the Tyrannosaurus Rex, detailing a unique serrated structure that let them chomp efficiently through the flesh and bones of large prey. (Photo by Maxi Jonas/Reuters)

Sepak Takraw – ISTAF Super Series Korea 2014-15 – Gunsan City, South Korea April 26, 2015: Thailand's Fueangfa (L) in action during the final. (Photo by Jeremy Lee/Reuters)