Members of the aerobatic patrol of helicopters of the Spanish Air Force (Patrulla Aspa) fly over San Lorenzo beach during an aerial exhibition in Gijon, northern Spain, northern Spain, July 24, 2016. REUTERS/Eloy Alonso - RTSJF7X

A boy jumps from one pontoon to another as he plays on the banks of the river Ganges in Allahabad, India, July 28, 2016. REUTERS/Jitendra Prakash - RTSK2KU

A child climbs onto a giant mockup laptop keyboard during a promotion event at a shopping centre in Beijing, China July 28, 2016. REUTERS/Thomas Peter TPX IMAGES OF THE DAY - RTSK329

Pilgrims wearing raincoats pray before the opening ceremony of World Youth Day in Krakow, Poland, July 26, 2016. REUTERS/David W Cerny - RTSJR9W

A veiled Saudi woman enjoys a ride in the new Snow City at Al Othaim Mall in Riyadh, Saudi Arabia July 26, 2016. Picture taken July 26, 2016. REUTERS/Faisal Al Nasser

People are seen watching hot air balloons fly overhead during a two-day international hot air balloon festival in Eshkol Park near the southern city of Netivot, Israel July 22, 2016. REUTERS/Amir Cohen TPX IMAGES OF THE DAY - RTSJ5FL

Jin Mao employees walk 340 meters above the ground around the newly opened Jin Mao tower skywalk in Shanghai, China, July 28, 2016. REUTERS/Aly Song - RTSK0HD

Belgian scientists Marjolein Vanoppen and Sebastiaan Derese demonstrate the use of a machine that turns urine into drinkable water and fertilizer using solar energy, at the University of Ghent, Belgium, July 26, 2016. REUTERS/Francois Lenoir - RTSJQG2

A delegate wears a "Trump's Wall: Latins Keep Out!!!" hat on the floor during the second day of the Democratic National Convention in Philadelphia, Pennsylvania, U.S., July 26, 2016. REUTERS/Jim Young - RTSJS9T

A visitor looks at a Titan Arum (Amorphophallus titanum), one of the world's largest and rare tropical flowers, native to Sumatra, at the Botanic Garden in Meise near Brussels, Belgium, July 28, 2016. REUTERS/Francois Lenoir - RTSK2PD