Students play in their school yard on the first day of the new school term at a primary school in Baghdad, October 18, 2015. (Photo by Ahmed Saad/Reuters)

German police officers take pictures as fireworks explode next to the Quadriga sculpture atop the Brandenburg gate during New Year celebrations in Berlin, Germany, January 1, 2017. (Photo by Fabrizio Bensch/Reuters)

A girl participates in a New Year calligraphy contest in Tokyo, Japan, January 5, 2017. (Photo by Kim Kyung-Hoon/Reuters)

Revelers of the “Societe des Champs Elysee” launch fireworks before boarding the Rampart-St. Claude street car line, which just opened last fall, to commemorate the official start of Mardi Gras season, in New Orleans, Friday, January 6, 2017. (Photo by Gerald Herbert/AP Photo)

Barneys New York launches Gaga's Workshop with the inflation of the Gaga Spider Balloon at the corner of 23rd and Broadway on November 21, 2011 in New York City. (Photo by Neilson Barnard/Getty Images for Barneys New York)

Workers attach 288 new Waterford Crystal Triangles on the 2012 Times Square New Year's Eve Ball at One Times Square on December 27, 2011 in New York City. (Photo by Jason Kempin/Getty Images)

A woman reacts as she joins around a thousand New Year swimmers, many in costume, braved freezing conditions in the River Forth in front of the Forth Rail Bridge during the annual Loony Dook Swim on January 1, 2013 in South Queensferry, Scotland. Thousands of people gathered last night to see in the New Year at Hogmanay celebrations in towns and cities across Scotland. (Photo by Jeff J. Mitchell)

Pantless people stand on a subway platform on January 13, 2013 in New York City. Thousands of people participated in the 12th annual No Pants Subway Ride, organized by New York City prank collective Improv Everywhere. During the afternoon winter event, participants boarded separate subway stops and removed their pants, pretending that they did not know each other. The event, refered to as a “celebration of silliness” is designed to make fellow subway riders laugh and smile. (Photo by Timothy A. Clary/AFP Photo)