Boys walk home for lunch from school in the village of Kogelo, west of Kenya's capital Nairobi, July 16, 2015. U.S. President Barack Obama visits Kenya and Ethiopia later this month. His ancestral home of Kogelo is home to Sarah Hussein Obama, his step-grandmother. The Kenyan village, burial place of Obama's father, features an open-pit goldmine, a pork butcher's, a school named after their most famous son and outdoor market stalls. Villagers get around by motorbike taxi or on foot while a donkey-cart transports water. Children, some of them named Obama in honour of the President, walk to and from school together. (Photo by Thomas Mukoya/Reuters)

Nadezhda Tolokonnikova, a member of the feminist punk band, p*ssy Riot, right, reads papers at a district court in Zubova Polyana 440 km southeast of Moscow in Russia's province of Mordovia, Friday, April 26, 2013. A Russian court is to consider whether one of the jailed p*ssy Riot members is eligible for early release. Nadezhda Tolokonnikova, in custody since her arrest in March 2012, is serving a two-year sentence for the band's irreverent protest against President Vladimir Putin in Moscow's main cathedral. Tolokonnikova's lawyer Irina Khrunova is at right. (Photo by Mikhail Metzel/AP Photo)

Fire over Vieira de Leiria, Portugal, on October 16, 2017 as a series of deadly wildfires broke out across Spain and Portugal as the approach of Hurricane Ophelia whipped up strong winds that fanned the flames. (Photo by Helio Madeiras/News Pictures)

A model (C) looks at her mobile phone while backstage before the araisara Sara Arai Collection show during China Fashion Week in Beijing on March 27, 2015. China Fashion Week runs from March 24 to March 31. (Photo by Wang Zhao/AFP Photo)

Black-headed gulls sit on pickets at a riverside in Tokyo, Japan, December 27, 2015. (Photo by Toru Hanai/Reuters)

Aleksandra Krunic, of Serbia, drops to the court after defeating Petra Kvitova, of the Czech Republic, during the third round of the 2014 U.S. Open tennis tournament, Saturday, August 30, 2014, in New York. (Photo by Kathy Willens/AP Photo)

A mother bear takes a dip in the water to cool off in the warm summer sun but refuses to leave her three youngsters behind – so they climb aboard her back. (Photo by Jon Langeland/Solent News & Photo Agency)

Russia's Alexandra Stepanova and Ivan Bukin perform during the ice dance free dance program at the Rostelecom Cup ISU Grand Prix of Figure Skating in Moscow November 15, 2014. (Photo by Grigory Dukor/Reuters)