South Korean university students prepare for an establishment ceremony of the Reserve Officer Training Corps (ROTC) for female cadets at Sookmyung Women's University on December 10, 2010 in Seoul, South Korea. The South Korean defense ministry has agreed to admit women into it's college-based Reserve Officers' Training Program for the first time since the program began in 1963. (Photo by Chung Sung-Jun/Getty Images)

United States Marine Corps Staff Sgt. Jason Itro yells at recruit Nancy Carbins January 15, 2003 after she grabbed another recruit in the pool in an attempt to stay afloat during swim training at the Combat Pool on Parris Island, SC. Under the watchful eyes of swim instructors, recruits are required to swim in full gear and learn limited strokes and breathing to stay afloat. Carbins broke a major rule by grabbing another recruit and submerging them both. (Photo by Stephen Morton/Getty Images)

A 2S5 Giatsint self- propelled gun fires during tactical exercises held by artillery detachments of the Russian Eastern Military District' s 5th Army at the Sergeyevsky training ground in Primorye Territory, Russia on March 21, 2017. Over 2500 servicemen practice combat skills received in 2017 winter training exercises. (Photo by Yuri Smityuk/TASS)

From stuffed elephants to picnics under power lines, Leipzig-born photographer Frank Herfort coaxes magical, colour-saturated tableaux from intriguing slices of everyday Russian life. Here: A lonely dog watches the mailboxes in a typical Moscow residential block. (Photo by by Frank Herfort/The Guardian)

A Russian air force technician reports to a pilot that a bomber is ready for a combat mission at Hemeimeem air base in Syria Wednesday January 20, 2016. Russian warplanes have flown over 5,700 combat missions since Moscow launched its air campaign in Syria on September 30, 2015. (Photo by Vladimir Isachenkov/AP Photo)

Activists and supporters of Ukrainian nationalist groups light flares during a rally to mark the third anniversary of the Euromaidan Revolution in downtown Kiev, Ukraine, 21 November 2016. About one thousand activists took park in the rally during which they burned tires on the Independence Square, destroyed the Russian bank Sberbank and broke windows in the office of a Ukrainian politician Viktor Medvedchuk, according to Ukrainian media. (Photo by Roman Pilipey/EPA)

Ivan Plakhuta, 54, the owner of a small workshop manufacturing valenki, Russian traditional footwear, rolls a valenok in the remote Siberian village of Bolshaya Rechka, located in Taiga area in the foothills of the Western Sayan Mountain Ridge in the Yermakovsky district of Krasnoyarsk region, Russia, November 10, 2015. (Photo by Ilya Naymushin/Reuters)

A Ukrainian man stands in protest in front of gunmen in unmarked uniforms as they stand guard in Balaklava, on the outskirts of Sevastopol, Ukraine, Saturday, March 1, 2014. (Photo by Andrew Lubimov/AP Photo)