Balal, who killed Iranian youth Abdolah Hosseinzadeh in a street fight with a knife in 2007, is brought to the gallows during his execution ceremony in the northern city of Nowshahr on April 15, 2014. The mother of Abdolah Hosseinzadeh spared the life of the her son's convicted murderer, with an emotional slap in the face as he awaited execution prior to removing the noose around his neck. (Photo by Araash Khamooshi/AFP Photo/ISNA)

Breitling Wingwalkers aircrafts perform during an aerobatic display at an air show in Zhengzhou, Henan province, China, September 25, 201. (Photo by Reuters/Stringer)

A stuffed rabbit doll sits among children's beds standing in the abandoned kindergarten of Kopachi village located inside the Chernobyl Exclusion Zone on September 29, 2015 near Chornobyl, Ukraine. Kopachi, a village that before 1986 had a population of 1,114, lies only a few kilometers south of the former Chernobyl nuclear power plant, where in 1986 workers inadvertantly caused reactor number four to explode, creating the worst nuclear accident in history. (Photo by Sean Gallup/Getty Images)

A racegoer uses the camera on her phone to check her hair on the opening day of the Grand National Festival at Aintree Racecourse on April 3, 2014 in Aintree, England. The three days of racing attracts thousands of racegoers and fans from across the world. The meeting culminates with millions of pounds being wagered on the runners taking part in Europe's richest jump race, the Grand National. (Photo by Christopher Furlong/Getty Images)

Star Wars actors on the Cantina set at Star Wars Celebration: The Ultimate Fan Experience held at the Anaheim Convention Center on Thursday, April 16, 2015, in Anaheim, Calif. (Photo by Richard Shotwell/Invision/AP Photo)

A Kashmiri woman walks on a footbridge as it rains in Srinagar, June 24, 2015. This year's monsoon rains in India are officially forecast to be only 88 percent of the long-term average. (Photo by Danish Ismail/Reuters)

Nino, a ten-year-old toreador apprentice of the French Tauromachy Centre, nicknamed El Nino, touches a practice bull at the bullring of Garons, near Nimes, September 25, 2013. Since 1983, the French Tauromachy Centre in Nimes has trained some 1,000 youths in the art of bullfighting. Twenty of them have gone on to become professional matadors, facing fighting bulls in the arena. Twice a week, students take courses with a matador to learn the movements and gestures of the bullfighter in the ring, but without an animal present. Students train with calves in the surrounding fields during spring, and regularly participate in beginner's bullfights (becerradas) without killing calves. Solal has been taking courses for three years and Nino, for just a year now. Both are normally enrolled in French public schools, but have one thought in mind – bullfighting. They share a passion linked to the city of Nimes, famous for its ferias and bullring. (Photo by Jean-Paul Pelissier/Reuters)

Indigenous Sahrawi girls play on an improvised see-saw at a refugee camp of Boudjdour in Tindouf, southern Algeria March 3, 2016. UN Secretary General Ban Ki-moon is scheduled to visit the Sahrawi refugees in south-west Algeria's Tindouf region. (Photo by Zohra Bensemra/Reuters)