A military band prepares to play the national anthems before Cuban President Raul Castro welcomes U.S. President Barack Obama at the Palacio de la Revolucion in Havana March 21, 2016. Barack Obama on Sunday became the first US president in 88 years to visit Cuba, touching down in Havana for a landmark trip aimed at ending decades of Cold War animosity. (Photo by Jonathan Ernst/Reuters)

In this Thursday, March 17, 2016 photo, 33-year-old Palestinian clown doctor Alaa Miqdad, left, entertains 3-year-old patient Yaqin Shawaf, who suffers from dialysis, in the department of kidney diseases at Al-Rantisi children's hospital in Gaza City. (Photo by Adel Hana/AP Photo)

People take part in the annual Easter Parade and Bonnet Festival along 5th Avenue in New York City March 27, 2016. The parade, which is more of a stroll than a parade, is more informal than the city's other parades. There are no bands, no floats, and no formations, and anyone can participate. (Photo by Brendan McDermid/Reuters)

A man suffering from mental illness sits chained on a bed in his room inside his family home in Curug Sulanjana village in Serang, Banten province, Indonesia March 23, 2016. In a programme launched this year, Indonesia sends teams of workers into often-remote hamlets to help free patients kept in chains and ensure they get the medical treatment they need. (Photo by Reuters/Beawiharta)

A child, from Municipal school Parana, poses during the project “Fencing School” in Rio de Janeiro, Brazil, March 30, 2016. Children in Rio de Janeiro lift their sights and their swords to new idols, as a round of fencing workshops takes to public schools. The International Fencing Federation, together with the Brazilian and state federations, will reach 40 public schools in March and April. The aim is to whip up a following for the Olympic sport, little known in the soccer-mad nation, as Rio sets the stage for the Summer Games in August. (Photo by Sergio Moraes/Reuters)

An ethnic Armenian fighter carries Kalashnikov machine guns to his comrade-in-arms at Martakert province in the separatist region of Nagorno-Karabakh, Azerbaijan, Monday, April 4, 2016. (Photo by Vahan Stepanyan/PAN Photo via AP Photo)

A pistol set made by Versailles gunsmith Nicolas-Noel Boutet and was gifted to Simon Bolivar from Marquis de La-fayette is displayed at Christie's auction house in the Manhattan borough of New York, April 5, 2016. (Photo by Lucas Jackson/Reuters)

A visitor poses inside a three story upside-down family sized house at the Huashan Creative Park in Taipei, Taiwan April 7, 2016. Over 300 square meters of floor space of the upside-down house, filled with home furnishings, was created by a group of Taiwanese architects at a total cost of around US$600,000 and took 2 months to complete, according to the organisers. (Photo by Tyrone Siu/Reuters)