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)

A demonstrator sits on the roadway during a protest against police brutality against minorities, in New York April 14, 2015. Protesters angered by fresh cases of police violence against unarmed black men in the United States gathered on Tuesday in New York City in a protest organized by the group “Stop Mass Incarceration Network” hoping to invigorate a national discussion on the thorny issue. (Photo by Brendan McDermid/Reuters)

Migrants with a stick, stones and knife fight with each other after a brawl erupted over a place in an overcrowded train heading to the Serbian border at the train station in Gevgelija, The Former Yugoslav Republic of Macedonia, 14 August 2015. The number of migrants passing through Macedonia increases day by day, local sources said. From the beginning of the year to mid-June 2015, nearly 160,000 migrants landed in the southern European countries, mainly Greece and Italy, on their way to wealthier countries in Western and Northern Europe, according to estimates by the International Organization for Migration (IOM). (Photo by Georgi Licovski/EPA)

Young girls take ballet lessons at the New Dreams dance studio in the Luz neighborhood known to locals as Cracolandia (Crackland) in Sao Paulo, Brazil, August 14, 2015. For the young girls learning to jump and plie, the dance studio provides a way forward and out of the difficult environment they have grown up in. Brazil is one of the world's highest consuming countries of crack cocaine, and Cracolandia, or “Crack Land”, located in the outskirts of Sao Paulo, is one of the most intense and brutal hubs. (Photo by Nacho Doce/Reuters)

Photographer Carlos Barria holds a print of a photograph he took in 2005, as he matches it up at the same location 10 years on, in Lafitte, south of New Orleans, United States, August 16, 2015. The print shows Tyler Teal cleaning up his home, September 14, 2005, after Hurricane Katrina struck. In 2005, Hurricane Katrina triggered floods that inundated New Orleans and killed more than 1,500 people as storm waters overwhelmed levees and broke through floodwalls. (Photo by Carlos Barria/Reuters)

A flood affected boy on a makeshift banana raft collects biscuit packets distributed by a government official from a boat in Pokoria village, east of Gauhati, north eastern Assam state, India, Monday, August 14, 2017. Heavy monsoon rains have unleashed landslides and floods that killed dozens of people in recent days and displaced millions more across northern India, southern Nepal and Bangladesh. (Photo by Anupam Nath/AP Photo)

A man in “Red Army” garb hits the pavement during a simulated attack during a re-staging of part of the Long March in Jinggangshan September 14, 2017. The scene brings alive an extraordinary chapter in China's history that established the supremacy of Chairman Mao Zedong and the Communist Party. Deep in the mountains of Jinggangshan in the southeastern province of Jiangxi, a classroom of bank tellers participates in an ideological boot camp that plays into Chinese President Xi Jinping's drive to further consolidate his grip on power. (Photo by Thomas Peter/Reuters)

A sadhu, or a Hindu holy man, blesses a devotee as he smokes marijuana at a transit camp on the way to Gangasagar, in Kolkata, India, Sunday, January 7, 2018. Thousands of Hindu pilgrims are expected to take the annual holy dip at Gangasagar, where the Ganges River reaches the Bay of Bengal, on the auspicious Makar Sankranti festival day that falls on Jan. 14. (Photo by Bikas Das/AP Photo)