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)

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)

Shepherds walk with sheep through the village on their way home during autumn redyk in Gron, Tatra Mountains region of southern Poland, October 6, 2015. Redyk is a traditional, kilometres-long march of highlanders with flocks of sheep, which takes place twice a year: in the spring at the start of the grazing season, and in the autumn at season's end. (Photo by Kacper Pempel/Reuters)

People use snowshoes during a tour of the Great Kemeri Bog, Latvia, October 17, 2015. The Kemeri bog is more than 8,000 years old and is one of the largest dry moss swamps in the Baltics. A more than decade-long joint restoration of the bog by the European Union and the Latvian government helped the bog recover its high moss marshes, damp black alder forests, floodplain meadows and seaside lakes – features now considered rare in Europe due to industrialisation. (Photo by Ints Kalnins/Reuters)

Sandstone sculpted by water and wind erosion is seen in a slot canyon, one of hundreds that surround Lake Powell near Page, Arizona, May 26, 2015. Lake Powell on the Colorado River provides water for Nevada, Arizona and California. A severe drought in recent years, combined with withdrawals that many believe are not sustainable, has reduced its levels to only about 42 percent of its capacity. (Photo by Rick Wilking/Reuters)

Men dressed as “Krampuss” prepare to parade at Munich's Christmas market, December 13, 2015. Young single men will wear the traditional attires known as “Krampusse”, consisting of animal skins and masks, with large cow-bells to make loud and frightening noises and parade through the city. They follow “Saint Nicholas” from house to house in December each year to bring luck to the good and punish the idle. (Photo by Michael Dalder/Reuters)

Miners search for jade stones at a mine dump at a Hpakant jade mine in Kachin state, Myanmar November 25, 2015. Using heavy earth-excavators and explosives, miners have been tearing into Myanmar's northern hills in recent months, in a rush to excavate more jade from the world's richest deposits of the gemstone before a new government takes office next year. (Photo by Soe Zeya Tun/Reuters)

A biker poses on his Bousouzoku motorbike at the Dangouzaka rest stop in Yamanashi, west of Tokyo, Japan, January 3, 2016. Police on Sunday halted a group of about two dozen Bousouzoku bikers who paraded their noisy motorcycles during an annual New Year outing in the Mount Fuji region. This Japanese motorcycle subculture dated back to the 1950s and regularly chafes with the police because of their provocative traffic behaviour and bike customising, that is often deemed illegal. (Photo by Thomas Peter/Reuters)