Cosplay fans attend the Animation Comic Games (ACG) Culture Festival in Xi'an, capital of northwest China's Shaanxi Province, May 28, 2017. The festival kicked off on Saturday, attracting lots of cosplay fans. (Photo by Liu Xiao/Xinhua)

Pernille Ferdinandsen receives a neck tattoo from Peter Madsen during the third Copenhagen Ink Festival which opened Thursday May 9, 2013 in Copenhagen, Denmark, the biggest tattoo festival in Northern Europe. During the three days, 180 of the world's best and most celebrated national and international tattoo artists show the audience their skills in making art on the body and tattoo's on the audience. (Photo by Lars Krabbe/AP Photo)

A passenger plane comes into land over a field containing horses at Heathrow Airport on August 11, 2014 in London, England. Heathrow is the busiest airport in the United Kingdom and the third busiest in the world. The airport's operator BAA wants to build a third runway to cope with increased demand. (Photo by Peter Macdiarmid/Getty Images)

Yana Shcherban of Russia looks at the ball after failing to receive it during their FIVB Women's Volleyball World Grand Prix 2014 final round against Japan in Tokyo August 20, 2014. (Photo by Yuya Shino/Reuters)

A hot air balloon flies close to the ground in the Jezreel Valley in northern Israel during an international hot air balloon festival October 14, 2014. (Photo by Nir Elias/Reuters)

Andrey Karr from Western Riders Slacklines at sunset above big waves in Nazare, Portugal on December 27, 2017. (Photo by Aidan Williams/National Geographic Travel Photographer of the Year Contest)

Jason Derulo (C) performs “Get Ugly” at the People's Choice Awards 2016 in Los Angeles, California January 6, 2016. (Photo by Mario Anzuoni/Reuters)

Surfer Arlen Macpherson sits on his board, which has an electronic shark repellent device installed, at Sydney's Bondi Beach in Australia, August 18, 2015. A spate of shark attacks in Australia has left some of world's top surfing beaches deserted and many people having second thoughts about taking a swim as the summer approaches. Macpherson paid A$390 for a device embedded in his surf board to repel sharks by emitting an electronic force field that overpowers its sensing organs. (Photo by David Gray/Reuters)