North Koreans wave as Hughes MD-500 helicopters fly past during an aerial display on Saturday, September 24, 2016, in Wonsan, North Korea. North Korea on Saturday opened an air festival featuring sky diving, demonstrations by its air force and lots of beer to promote a newly renovated and upgraded commercial airport in the coastal city of Wonsan that it hopes will draw for foreign tourists. (Photo by Wong Maye-E/AP Photo)

A woman sandboards on the mountain in Wadi el-Rayan Fayoum, Egypt, November 18, 2016. (Photo by Mohamed Abd El Ghany/Reuters)

A hot air balloon in the likeness of Yoda from Star Wars prepares for liftoff at the 21st Philippine International Hot Air Balloon Festival at the former Clark US Air Force base in Pampanga Province, Philippines on February 9, 2017. (Photo by Xinhua News Agency/Rex Features/Shutterstock)

Soldiers stand in front of a floral decoration during celebrations to commemorate the 70th anniversary of the establishment of the Vietnam People's Army at the National Convention Center in Hanoi December 20, 2014. The Vietnam People's Army was founded on December 22, 1944 and led by General Vo Nguyen Giap in Cao Bang province, initially with only 34 members. (Photo by Reuters/Kham)

A supporter welcomes US army convoy as it enters Czech Republic in Harrachov, Sunday, March 29, 2015. The “Dragoon Ride” convoy started last week from Estonia and passed through Latvia, Lithuania and Poland before entering the Czech Republic on a return journey to a German base. (Photo by Petr David Josek/AP Photo)

A farmer is seen hanging from a tree during a rally organized by Aam Aadmi (Common Man) Party (AAP) in New Delhi April 22, 2015. The farmer hanged himself from a tree during a political rally in New Delhi on Wednesday, in what appeared to be a desperate protest against the hardship felt by many people scratching a living in rural India. Four people climbed the tree to try to save the man after he was seen hanging. (Photo by Adnan Abidi/Reuters)

A model wearing a creation by Luis Benitez poses during an urban shoot as part of Andalucia de Moda (Andalusia Fashion) at the aquarium of Seville, southern Spain, November 11, 2015. (Photo by Marcelo del Pozo/Reuters)

Cameron Shonnard backflips a jump at Squaw Valley in Olympic Valley, California, December 5, 2015. An El Nino is forecasted for California, and regular precipitation has been welcomed after years of drought. (Photo by Max Whittaker/Reuters)