A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via AP Photo)

Alexo Carmona, 2, looks at Coco, a two-year-old pony, in downtown Havana, in this March 6, 2015 file photo. Nearly a quarter of a million people follow the Reuters Instagram account – and it's still growing fast. To mark the mid-point of 2015, Reuters has compiled the twenty most-liked pictures so far. This picture was 20th most popular. (Photo by Alexandre Meneghini/Reuters)

Men carry others, so they do not soil their shoes and clothes, through a mudslide caused by Tropical Storm Erika in Carries, Haiti, August 29, 2015. Erika, a tropical storm that killed 20 people on the Caribbean island of Dominica and at least one person in Haiti, fell apart on Saturday over eastern Cuba, the U.S. National Hurricane Center said. (Photo by Andres Martinez Casares/Reuters)

A U.S. Army B-24 Liberator Bomber is hailed by a ground crewman as it takes off over a line of shark- nosed fighter planes at an advanced base in China on a mission on October 10, 1943, to bomb Japanese installations. (Photo by AP Photo)

A man carries a dog and wades through a flooded street in Chennai, in the southern Indian state of Tamil Nadu, Wednesday, December 2, 2015. Weeks of torrential rains have forced the airport in the state capital Chennai to close and have cut off several roads and highways, leaving tens of thousands of people stranded in their homes, government officials said Wednesday. (Photo by AP Photo)

Performers eat their lunch before the start of the New Year's Day Parade in London, January 1, 2016. (Photo by Kevin Coombs/Reuters)

Samburu tribesmen stand during the Maralal Camel Derby, Kenya, August 15, 2015. Maralal, a small, arid town about an eight-hour drive north of the Kenyan capital Nairobi, holds an annual camel festival, bringing together members of the Samburu, Turkana and Pokot semi-nomadic cattle-herding tribes. (Photo by Goran Tomasevic/Reuters)

A Naga sadhu, or naked Hindu holy man, pauses inside a tent during Kumbh Mela, or Pitcher festival, at Trimbakeshwar, India, Thursday, August 27, 2015. Hindus believe taking a dip in the waters of a holy river during the festival will cleanse them of their sins. The festival is held four times every 12 years. (Photo by Bernat Armangue/AP Photo)