United States Marines perform a fighting demonstration in Times Square as part of Fleet Week festivities May 27, 2011 in New York City. Fleet Week, which has been held in New York since 1984, brings thousands of military members to the city where they engage the public with numerous activities, demonstrations, tours and contests. Fleet Week concludes on Memorial Day with a military flyover to honor those killed while serving in the military. (Photo by Spencer Platt/Getty Images)

In this March 18, 2015 photo, a boy rides a mechanical bull for children at the Texcoco Fair on the outskirts of Mexico City. In Mexico, these types of fairs date back to Spanish colonial times, and in some smaller communities they are organized around the feast days of Roman Catholic saints. (Photo by Eduardo Verdugo/AP Photo)

A World War II re-enactor dressed as Red Army soldiers rests after a staged battle to mark the liberation of the city of Ostrava by Red Army from the Nazi invaders in 1945, Czech Republic, Thursday, April 30, 2015. (Photo by Sergei Grits/AP Photo)

Firefighters attempt to put out a fire at an abandoned building with the protection of St. Louis City Police in St. Louis, Missouri August 19, 2015. Police fatally shot a black man they say pointed a gun at them, drawing angry crowds and recalling the racial tensions sparked by the killing of an unarmed African-American teen in nearby Ferguson, Missouri, just over a year ago. (Photo by Lawrence Bryant/Reuters)

Newly-wed couples attend their group wedding ceremony which was held as part of the Harbin International Ice and Snow Festival in the northern city of Harbin, Heilongjiang province January 6, 2016. As many as 15 couples attend this mass wedding ceremony. (Photo by Aly Song/Reuters)

In this Monday, January 18, 2016 photo, Iranian rock climber, Farnaz Esmaeilzadeh, scales a climbing gym in the city of Zanjan, some 330 kilometers (207 miles) west of the capital Tehran, Iran. Esmaeilzadeh, 27, who has been climbing since she was 13, has distinguished herself in international competitions despite the barriers she faces as a female athlete in conservative Iran. (Photo by Ebrahim Noroozi/AP Photo)

Characters dressed as Elmo and Cookie Monster who pose for tips take a photo by request from a tourist (2nd R, black pants) in Times Square in the Manhattan borough of New York City, January 29, 2016. (Photo by Rickey Rogers/Reuters)

Women pose for a picture at Havana city, Cuba, March 17, 2016. Obama arrives in Havana on Sunday for a historic visit that seals a rapprochement he and Cuban President Raul Castro agreed in December 2014 after 18 months of secret negotiations. (Photo by Ivan Alvarado/Reuters)