A student from the General Yermolov Cadet School takes part in weapons training during a two-day field exercise near the village of Sengileyevskoye, just outside the south Russian city of Stavropol April 13, 2014. The General Yermolov Cadet School in the southern Russian city of Stavropol is a state-run institution that teaches military and patriotic classes in addition to a normal syllabus. (Photo by Eduard Korniyenko/Reuters)

Vehicles and weapons of the Justice and Equality Movement (JEM) rebels are seen on display, after victory celebrations by the Sudanese Armed Forces (SAF) and the Rapid Support Forces (RSF), in Niyala Capital of South Darfur, May 4, 2015. (Photo by Reuters/Stringer)

A man looks at the wax figure of Marilyn Monroe at Grevin Wax Museum in central Seoul, South Korea, July 30, 2015. French wax museum Musee Grevin has opened its first Asian branch in central Seoul with about 80 wax figures including those from hallyu (the Korean pop culture wave) displayed, according to local media. (Photo by Kim Hong-Ji/Reuters)

A girl watches as Saen Dao, an eight-year-old female asian elephant, and her mahout perform underwater during a show at the Khao Kheow Open Zoo in Chonburi south of Bangkok on June 1, 2017. (Photo by Roberto Schmidt/AFP Photo)

Men slide in the mud during the Boryeong Mud Festival at Daecheon Beach in Boryeong, South Korea, Saturday, July 22, 2017. The 20th annual mud festival features mud wrestling and mud sliding. (Photo by Ahn Young-joon/AP Photo)

A woman poses for photographs with traditional side dish Kimchi during the Seoul Kimchi Festival in central Seoul, South Korea, November 4, 2016. Kimchi made with cabbage, other vegetables and chili sauce and kimchi is the most popular traditional food in Korea. (Photo by Kim Hong-Ji/Reuters)

A woman tour skates on the frozen lake of Orlangen, south of Stockholm, Sweden, on December 23, 2016. Tour skating is recreational long distance ice skating on natural ice particularly popular in the Nordic countries. (Photo by Tobias Roestlund/AFP Photo/TT News Agency)

An employee controls the arms of a manned biped walking robot “METHOD-2” during a demonstration in Gunpo, South Korea, December 27, 2016. It stands 13-feet (3,96 m) tall, weighs 1.3 tons and wields a pair of 286-pound (129,73 kg), motion-tracking metal arms. (Photo by Kim Hong-Ji/Reuters)