Couples take part in the “Love and Challenge Marathon” in Hanoi, Vietnam, 16 August 2015. Fifty couples, who are going to get married, participated in the event which is held the fifth time. This year, the winners of the marathon received a honeymoon trip to Malaysia. (Photo by Luong Thai Linh/EPA)

Russian President Vladimir Putin (R) looks through a window of a research bathyscaphe while submerging into the waters of the Black Sea as he takes part in an expedition near Sevastopol, Crimea, August 18, 2015. (Photo by Alexei Nikolsky/Reuters/RIA Novosti/Kremlin)

People look at revellers (L) waiting to take part in a LGBT (lesbian, gay, bisexual and transgender) pride parade to mark Gaijatra Festival, also known as the festival of cows, in Kathmandu, Nepal, August 30, 2015. Hundreds of lesbians, gays, bisexuals and transvestites paraded through Nepal's capital Sunday to demand that rights for sexual minorities be included in the country's new constitution that is being finalized. (Photo by Navesh Chitrakar/Reuters)

Competitors take part in the 8th annual World Gravy Wrestling Championships at the Rose n Bowl Pub in Bacup, north west England on August 31, 2015. Contestants must participate in fancy dress and wrestle in a pool of Lancashire Gravy for 2 minutes whilst being scored for a variety of wrestling moves. (Photo by Oli Scarff/AFP Photo)

A reveller wearing a demon costume takes part in the traditional festival of “Correfoc” in Palma de Mallorca, on January 17, 2015. The Correfoc is a night of revelry in which participants dress as demons and devils, and move through the streets scaring people with fire and fireworks. (Photo by Jaime Reina/AFP Photo)

Ukrainians swim in an ice hole as part of the celebration of the Epiphany in Kiev, Ukraine, Monday, January 19, 2015. Orthodox believers celebrate the holiday of the Epiphany on Jan. 19, and traditionally bathe in holes cut through thick ice on rivers and ponds to cleanse themselves with water deemed holy for the day. (Photo by Sergei Chuzavkov/AP Photo)

Dogs rest during the Sedivackuv Long dog sled race in Destne v Orlickych horach January 23, 2015. Each year, racers from all over Europe arrive at the village of Destne in the Orlicke mountains in Czech Republic to take part in the race. (Photo by David W. Cerny/Reuters)