Three-years-old dog Hope uses a wheelchair to run next to its owner Regine Grosinger in Vienna September 3, 2014. Hope was found with cut-off back legs in the countryside and brought to an animal asylum when it was four-month-old. Grosinger took the dog home two months later and had a wheelchair manufactured for it. (Photo by Heinz-Peter Bader/Reuters)

Pedestrians and workers pass an upside down car art installation in a car park on the South Bank in London, February 19, 2015. British artist Alex Chinneck's illusory piece, entitled “Pick yourself up and pull yourself together”, and on display in the working car park for a week, sees a Vauxhall car suspended upside down, appearing to be gripping onto a peeled back length of tarmac. (Photo by Toby Melville/Reuters)

Militants loyal to Yemen's exiled government ride on the back of a pick-up truck in the country's central city of Taiz August 19, 2015. Militia forces loyal to Yemen's exiled government fought their way deep into the central city of Taiz this week, local officials said, largely pushing out Houthi militiamen from the country's third largest city. (Photo by Reuters/Stringer)

Vivian Odhiambo, 24, frys samosas in the trading centre of Kogelo, west of Kenya's capital Nairobi, July 14, 2015. Odhiambo said, “Obama is our hero and we wait to welcome him back home again. We in Kogelo have witnessed general growth and we are proud of being associated with the Obamas”, she added. As U.S. President Barack Obama visits Kenya, a personal connection to his father's birthplace of Kogelo dominates a trip that Kenyans view as a native son returning home. Residents from a herdsman to a housewife share their views on what Obama has achieved and what they would like to see next. (Photo by Thomas Mukoya/Reuters)

Rougine, a 19-year-old female Arab fighter among the Syrian Democratic Forces, made up of US-backed Kurdish and Arab fighters, stands in fatigues embracing another colleague near the village of al-Torshan, 20 km on the outskirts of Raqa on February 6, 2017. (Photo by Delil Souleiman/AFP Photo)

A Syrian man rides his bicycle past a man selling grains during a halt in fighting on February 29, 2016 in Douma, in the Eastern Ghouta region, east of the capital Damascus. A UN-backed ceasefire deal took hold across parts of Syria, bringing relative calm to areas where the Islamic State group and Al-Qaeda's local affiliate are not present. (Photo by Sameer Al-Doumy/AFP Photo)

Girls sleep in the back of their father's moto-taxi as he watches them from the front seat, days after an earthquake in Pedernales, Ecuador, Wednesday, April 20, 2016. A fresh tremor rattled Ecuador before dawn Wednesday, a magnitude-6.1 jolt that set babies crying and shaken residents pouring once again into the streets, fearful of yet more damage following a monster earthquake over the weekend. (Photo by Dolores Ochoa/AP Photo)

Participants in traditional dress ride on horseback as they enjoy the atmosphere at the Feria de Abril (April's Fair) on April 12, 2016 in Seville, Spain. The Feria de Abril has a history that dates back to 1857 and takes place a fortnight after Easter each year. The origin of the fair was a cattle market but the event quickly turned its goal from commerce to having fun. More than 1 million local and international participants are expected to attend the Feria de Abril. (Photo by David Ramos/Getty Images)