A dog swims as a resident navigates his boat in a neighbourhood flooded by the Purus river, which continues to rise from days of heavy rainfall in the region, in Boca do Acre, Amazonas state March 14, 2015. According the state civil defense, more than 20,000 people have been left homeless along the Purus river, where incessant rains have flooded the area and caused the river to burst their banks. (Photo by Bruno Kelly/Reuters)

Pope Francis greets the crowd from his popemobile in downtown Rio de Janeiro. Pope Francis touched down in Rio de Janeiro on Monday, starting his first foreign trip as pontiff and a weeklong series of events expected to attract more than a million people to a gathering of young faithful in Brazil, home to the world's largest Roman Catholic population. (Photo by Ueslei Marcelino/Reuters)

Carnival revellers dressed as “Peliqueiros” run along a street in the village of Laza, Spain February 26, 2017. “Peliqueiros”, or ancient tax collectors, pursued villagers through the streets ringing their cowbells and hitting villagers with their sticks. (Photo by Miguel Vidal/Reuters)

A masked reveller poses near Saint Mark's Square during the Venetian Carnival in Venice January 31, 2015. (Photo by Stefano Rellandini/Reuters)

A member of the “Morenada Los Cocanis” group dances during the Carnival parade in Oruro February 14, 2015. Thousands of dancers and tourists attend the carnival celebrations in Oruro, south of La Paz. (Photo by David Mercado/Reuters)

A reveler participates in a parade on the streets during a carnival to mark the annual Orthodox St. Vasilij Day in the village of Vevcani, south of the Macedonian capital of Skopje, January 13, 2017. (Photo by Ognen Teofilovski/Reuters)

Assi Mbengue nibbles as she prepares for the start of Las Palmas' Carnival Queen ceremony in Las Palmas, Spanish Canary Island of Gran Canaria, February 24, 2017. (Photo by Borja Suarez/Reuters)

Dancers perform at a Carnival parade in Les Cayes, Haiti, Tuesday, February 28, 2017. Haiti's three-day Carnival festivities have brought rum-fueled parties, imaginative costumes and high-energy dance music to a southern city that's still recovering from last year's punishing Hurricane Matthew. (Photo by Dieu Nalio Chery/AP Photo)