Members of Hashid Shaabi or Popular Mobilization Forces (PMF) fire towards Islamic State militant positions in west of Mosul, Iraq, December 28, 2016. (Photo by Reuters/Stringer)

An Israeli Air Force F-35 fighter jet flies during an aerial demonstration at a graduation ceremony for Israeli airforce pilots at the Hatzerim air base in southern Israel December 29, 2016. (Photo by Amir Cohen/Reuters)

98-year-old beggar, the grandfather of the Bulgarian village of Dobri Bail, wearing homespun clothes and old leather shoes he wears in winter and summer, often standing at the Cathedral of St. Alexander Nevsky Cathedral in Sofia. Every day he gets up early and runs 10 kilometers from their village Bail to the Bulgarian capital.

The “Naked Cowboy” plays his guitar in Times Square on March 23, 2012 in New York City. A recent study found that the Times Square district contributes up to 10% of all jobs in the city and is responsible for approximately 11% of economic activity. (Photo by Andrew Burton/Getty Images)

A baby Asian elephant, born only two days before, stands next to his mother Nova in its enclosure at Tierpark Berlin Zoo on May 10, 2012 in Berlin, Germany. The male elephant calf, who does not have a name yet, weighs 102kg and is 91cm tall. (Photo by Timur Emek/dapd/Sean Gallup)

Lítla Dímun is a small island between the islands of Suðuroy and Stóra Dímun in the Faroe Islands of Denmark. It is the smallest of the main 18 islands, being less than 100 hectares (250 acres) in area, and is the only uninhabited one. The island can be seen from the villages Hvalba and Sandvík.

A gaggle of geese graze in a field at Holly Tree Farm in the Cheshire countryside as they are fattened up for Christmas on November 10, 2011 in Knutsford, England. Roasted goose is gaining in popularity as an alternative to turkey during the Christmas meal of the festive period. (Photo by Christopher Furlong/Getty Images)

In this photo illustration a package of Nicotine Gum, which is advertised as helping people stop smoking cigarettes, is seen on January 10, 2012 in Miami, Florida. A study published in the journal Tobacco Control on Monday, reported that the nicotine alternatives, like Nicotine Gum, have no lasting effect on people trying to quit their smoking habit. (Photo illustration by Joe Raedle/Getty Images)