Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

Participants prepare backstage during Belarus bodybuilding and fitness championship in Minsk April 25, 2015. (Photo by Vasily Fedosenko/Reuters)

Emilio Gonzalez from Venezuela poses during the Cali Tattoo Festival in Cali, Colombia, September 12, 2015. (Photo by Jaime Saldarriaga/Reuters)

People are reflected in a shop window as they walk along a street in a shopping district in Tokyo, Japan June 25, 2015. (Photo by Thomas Peter/Reuters)

A migrant boy sits on railway tracks at a train station in Tovarnik, Croatia, September 20, 2015. (Photo by Antonio Bronic/Reuters)

Competitors warm up backstage during the Arnold Classic Europe bodybuilding event in Madrid, Spain, September 25, 2015. (Photo by Susana Vera/Reuters)

A dog catches a wave during the Surf City Surf Dog Contest in Huntington Beach, California September 27, 2015. (Photo by Lucy Nicholson/Reuters)

Women take part in Belarus Cup in bodybuilding and fitness in Minsk, October 24, 2015. (Photo by Vasily Fedosenko/Reuters)