A marine aims an RPG-7, a portable rocket- propelled grenade launcher, during military exercises conducted by the Russian Pacific Fleet' s naval infantry unit at the Bamburovo firing range on February 2, 2017. The drills are a part of preparations for the Suvorov Attack and Sniper Line army competitions. (Photo by Yuri Smityuk/TASS)

A woman sweeps an alleyway adorned with murals painted by artists from “Delhi Street Art” group at the Raghubir Nagar slum in New Delhi on December 2, 2019. A New Delhi slum has been given a colourful makeover thanks to a street artist collective, drawing art lovers and selfie-snappers to a rundown area that they would never normally visit. (Photo by Sajjad Hussain/AFP Photo)

A fan cosplays as Aloy from Horizon Zero Dawn during the 2017 New York Comic Con, Day 4 on October 8, 2017 in New York City. (Photo by Roy Rochlin/WireImage)

Children wearing uniforms hold toy guns during a military parade game on China's National Day, at Beyou World, a centre children where can experience different kinds of professions, in Beijing, October 1, 2015. (Photo by Reuters/Stringer)

People attend a Halloween event at Ocean Park on October 30, 2015 in Hong Kong. Halloween – a named taken from 'All Hallows' Even' falls on the day before All Saints' Day on November 1 – a holiday when Christians remember their deceased loved ones. (Photo by Anthony Kwan/Getty Images)

Graffiti is painted on the bathroom walls at a restaurant in the Williamsburg area of Brooklyn borough in New York, United States, October 1, 2015. Some 2.4 billion people around the world don't have access to decent sanitation and more than a billion are forced to defecate in the open, risking disease and other dangers, according to the United Nations. To mark World Toilet Day on November 19, Reuters photographers captured pictures of toilets in cities, towns and villages around the globe. (Photo by Shannon Stapleton/Reuters)

A Filipino transgender woman holds a huge red ribbon symbolizing fight against the HIV virus as she poses before photographers, during a World Aids Day celebration in Manila, Philippines, December 1, 2015. (Photo by Erik De Castro/Reuters)

Comic club member Michael Kenney pauses on South Broad Street to adjust his costume during the 116th annual Mummers Parade in Philadelphia on Friday, January 1, 2016. Outrageously costumed Mummers strutted their stuff Friday at the city's annual New Year's Day parade, a colorful celebration that features string bands, comic brigades, elaborate floats and plenty of feathers and sequins. (Photo by Joseph Kaczmarek/AP Photo)