A Syrian migrant family enters Hungary at the border with Serbia near Roszke, Hungary August 28, 2015. As Europe struggles with its worst migrant crisis since World War II, Hungary has become, like Italy and Greece, a “frontline” state. So far this year, police say around 141,500 migrants have been intercepted crossing into Hungary, mostly from neighbouring Serbia. (Photo by Bernadett Szabo/Reuters)

Iraqi army soldiers attempt to move their truck stuck in the mud near the village of Al-Boutha al-Sharqiyah, west of Mosul, on December 2, 2016, during a broad offencive by Iraq forces to retake the main hub city from Islamic State group jihadists. (Photo by Ahmad Al-Rubaye/AFP Photo)

An airplane is silhouetted at sunrise, seen from the suburb of Saint-Cloud, near Paris, France, 08 December 2016. Paris is undergoing a third day pollution spike, prompting the city to limit vehicle circulation. (Photo by Ian Langsdon/EPA)

A Maasai moran athlete has his face smeared with red ocher paint during preparations for the 2016 Maasai Olympics at the Sidai Oleng Wildlife Sanctuary, at the base of Mt. Kilimanjaro, near the Kenya-Tanzania border in Kimana, Kajiado, Kenya December 10, 2016. (Photo by Thomas Mukoya/Reuters)

One of three Sperm Whales, which were found washed ashore near Skegness over the weekend, lays on a beach on January 25, 2016 in Skegness, England. The whales are thought to have been from the same pod as another animal that was found on Hunstanton beach in Norfolk on Friday. (Photo by Dan Kitwood/Getty Images)

People enjoy a bath in hot kvass, a traditional fermented beverage made from rye bread, during the sauna marathon near Otepaa, Estonia, February 6, 2016. Participants have to track down and visit the given saunas in the Otepaa area as fast as possible. (Photo by Ints Kalnins/Reuters)

Refugees and migrants try to find a place on an already full train headed for Serbia, near the city of Gevgelija, The Former Yugoslav Republic of Macedonia, on February 24, 2016. Refugees and migrants from Iraq and Syria continue to pass through Macedonia on their way to the European Union. (Photo by Georgi Licovski/EPA)

A musher handler with Alan Eischens team embraces one of Eischen's dogs just before the ceremonial start of the Iditarod Trail Sled Dog Race that begins a near 1,000-mile (1,600-km) journey through Alaska’s frigid wilderness in downtown Anchorage, Alaska March 5, 2016. (Photo by Nathaniel Wilder/Reuters)