Devotees ride on the roof of a train as they return to the city after attending the final prayers on the first phase of Bishwa Ijtema in Dhaka January 11, 2015. Hundreds of thousands of pilgrims congregated in the Bangladeshi capital Dhaka as the first phase of this year's Bishwa Ijtema, one of the biggest Islamic gatherings in the world after the Haj in Saudi Arabia, came to an end. (Photo by Reuters/Stringer)

A boy runs past one of the exhibits during the Dinosaurs exhibition in Belgrade, Serbia, Thursday, August 21, 2014. “Dino Park” has opened at Belgrade's Kalemegdan Fortress. (Photo by Darko Vojinovic/AP Photo)

This handout picture taken on September 30, 2017 and released on October 4, 2017 by the Batang Gansal Police shows villagers beside a 7.8 metre (25.6 foot) long python which was killed after it attacked an Indonesian man, nearly severing his arm, in the remote Batang Gansal subdistrict of Sumatra island Hungry locals later killed the snake and displayed its carcass in the village before dicing it up, frying it and feasting on it. (Photo by AFP Photo/Batang Gansal Police)

A female sniper of the Syrian Democratic Forces (SDF) monitors the area during a celebration at the iconic Al- Naim square in Raqa on October 19, 2017, after retaking the city from Islamic State (IS) group fighters. The SDF fighters flushed jihadist holdouts from Raqa' s main hospital and municipal stadium, wrapping up a more than four- month offensive against what used to be the inner sanctum of IS' s self- proclaimed “caliphate”. (Photo by Bulent Kilic/AFP Photo)

A participant in costume uses a mobile phone at a Halloween event in Kawasaki, south of Tokyo, Japan October 29, 2017. (Photo by Kim Kyung-Hoon/Reuters)

In this photograph taken on October 27, 2017 an Afghan woman collects saffron flowers after picking them in a field on the outskirt of Herat For years, Afghanistan has tried to give farmers alternatives such as fruit crops and saffron to wean them away from poppy farming – the lifeblood of the Taliban insurgency. International donors have splurged billions of dollars on counter- narcotics efforts in Afghanistan over the past decade, including efforts to encourage farmers to switch to other cash crops such as saffron. But those efforts have shown little results. (Photo by Hoshang Hashimi/AFP Photo)

An Indian nomadic shepherd from the western Rajasthan state guides his flock of sheep through an access road in Greater Noida, outskirts of New Delhi, India, Tuesday, December 5, 2017. Looking for suitable pasture lands for grazing, shepherds migrate their flocks over extensive areas in the same state or to neighboring states in India. (Photo by R.S. Iyer/AP Photo)

Yippie leader Jerry Rubin, barred on December 4, from House Un-American Activities subcommittee hearing, aims a toy gun in “self defense” outside the Washington hearing room on December 5, 1969. Rubin showed up in his Santa Clause suit because he believed it was typical of the committee which, he said, “is a total circus”. (Photo by Bob Daugherty/AP Photo)