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)

Members of the Uniao da Ilha do Governador Samba School perform during the first day of the Special Group Samba Schools parade of Carnival at the Sambadrome in Rio de Janeiro, Brazil, 07 February 2016. (Photo by Luiz Eduardo Perez/EPA)

Brazilians in favor of the impeachment of President Dilma Rousseff demonstrate as the Lower House of Congress voted over her impeachment in Brasilia, Brazil April 17, 2016. The sign reads, “The people want justice. Prison for the corrupt”. (Photo by Adriano Machado/Reuters)

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)

Yawalapiti children play during the preparations for the celebration of “quarup”, a ritual held to honor in death a person of great importance to them, in the Xingu National Park, Mato Grosso State, May 7, 2012. (Photo by Ueslei Marcelino/Reuters)

An aerial view of the Atibainha dam, part of the Cantareira reservoir, during a drought in Nazare Paulista, Sao Paulo state November 18, 2014. Brazil's worst drought in 80 years has left the Cantareira system, that provides greater Sao Paulo with most of its water, with the lowest water level on record, with daily rationing becoming common in the region's smaller cities, according to the state authorities and the two main reservoirs serving metropolitan Sao Paulo, South America's largest city, could dry out by February if relief does not arrive in the upcoming rainy season. (Photo by Nacho Doce/Reuters)

A woman, covered in mud, dances during the traditional “Bloco da Lama” or “Mud Block” carnival party, in Paraty, Brazil, Saturday, February 14, 2015. Revelers in the seaside colonial town threw themselves into deposits of black, mineral-rich slime, emerging covered head-to-toe in the sludge. Bikinis and trunks disappeared beneath the mud, which highlights both gym-pumped pectorals and beer-fed guts. (Photo by Leo Correa/AP Photo)

A policeman looks at a car crushed underneath a collapsed bridge in Belo Horizonte, Brazil, Thursday, July 3, 2014. The overpass under construction collapsed Thursday in the Brazilian World Cup host city. The incident took place on a main avenue, the expansion of which was part of the World Cup infrastructure plan but, like most urban mobility projects related to the Cup, was not finished on time for the event. (Photo by Victor R. Caivano/AP Photo)