Migrants storm into a train at the Keleti train station in Budapest, Hungary, September 3, 2015 as Hungarian police withdrew from the gates after two days of blocking their entry. (Photo by Laszlo Balogh/Reuters)

A student attending a winter military camp reacts during a training session in Ansan, south of Seoul January 3, 2013. Hundreds of students between 11 and 17 years old attend winter boot camp training courses every year. The winter courses range from 4 to 14 days at the Blue Dragon Camp run by retired marines, which also offers summer boot camp for students. (Photo by Kim Hong-Ji/Reuters)

A female Marine prepares to throw a practice grenade during Marine Combat Training (MCT) on February 21, 2013 at Camp Lejeune, North Carolina. Since 1988 all non-infantry enlisted male Marines have been required to complete 29 days of basic combat skills training at MCT after graduating from boot camp. MCT has been required for all enlisted female Marines since 1997. About six percent of enlisted Marines are female. (Photo by Scott Olson)

A young boy rests by empty USAID vegetable oil tins in the Dagahaley refugee camp which makes up part of the giant Dadaab refugee settlement on July 19, 2011 in Dadaab, Kenya. The refugee camp at Dadaab, located close to the Kenyan border with Somalia, was originally designed in the early 1990s to accommodate 90,000 people but the UN estimates over 4 times as many reside there. The ongoing civil war in Somalia and the worst drought to affect the Horn of Africa in six decades has resulted in an estimated 12 million people whose lives are threatened. (Photo by Oli Scarff/Getty Images)

Migrants prepare their food outside shelters in a muddy field called the Grande-Synthe jungle, near Dunkirk, northern France, January 12, 2016. The Grande-Synthe jungle is a camp of tents and makeshift shelters where migrants and asylum seekers from Irak, Kurdistan and Syria gather. (Photo by Benoit Tessier/Reuters)

This August 15, 2016 photo shows two portraits Carolina, one of her holding a weapon while in her uniform for the Revolutionary Armed Forces of Colombia (FARC) 49th front, and in civilian clothing at a guerrilla camp in the southern jungle of Putumayo, Colombia. Carolina, 18, said she has spent three years in the FARC and would like to study engineering after demobilizing as part of a peace deal with Colombia's government. (Photo by Fernando Vergara/AP Photo)

A Colombian Nukak Maku Indian boy gestures in a refugee camp at Agua Bonita near San Jose del Guaviare of Guaviare province September 3, 2015. Since emerging from the jungle in 2005, half naked and carrying blowpipes, the Nukak have lived in settlements near the frontier town of San Jose del Guaviare, a humid outpost in the Amazon 400 km (250 miles) southeast of the capital Bogota. (Photo by John Vizcaino/Reuters)

A Thai Marine instructor drinks a cobra's raw blood after killing it as he gives instruction to US Marines and South Korean Marines during jungle survival training as part of the multinational joint military exercise Cobra Gold 2018 at a Force Reconnaissance Battalion camp in the Royal Thai Naval Base, Sattahip district, Chonburi province, Thailand, 19 February 2018. (Photo by Rungroj Yongrit/EPA/EFE)