Fighters of the Free Syrian Army fire an anti-aircraft weapon in the rebel-held Mashhad area in southeastern Aleppo, on December 12, 2016, as they battle Syrian government forces during an operation to retake the embattled city. The crucial battle for Aleppo entered its “final phase” after Syrian rebels retreated into a small pocket of their former bastion in the face of new army advances. The retreat leaves opposition fighters confined to just a handful of neighbourhoods in southeast Aleppo, the largest of them Sukkari and Mashhad. (Photo by AFP Photo/Stringer)

Guests have breakfast as another guest climbs to gather at the Skylodge Adventure Suites in the Sacred Valley in Cuzco, Peru, August 14, 2015. Tourists taking on an arduous climb up the steep cliff face of Peru's Sacred Valley are being rewarded for their efforts by being able to spend the night in transparent mountaintop sleeping pods at the “Skylodge Adventure Suites”. To reach the pods, visitors need to climb 400 metres of via ferrata (a steel cable and rungs) up the valley side or hike an intrepid trail through zip lines. (Photo by Pilar Olivares/Reuters)

Cardboard cut outs of the faces of three candidates for the Republican nomination for the 2016 US Presidential election (L-R) Ted Cruz, Donald Trump and Marco Rubio, are seen set up on urinals in a pub in London on March 1, 2016 as part of an informal poll for customers to log which they dislike the most. Part of the satirical television show The Last Leg, customers at the pub are able to choose which urinal to use and then log their poll on a list on the wall afterwards. (Photo by Justin Tallis/AFP Photo)

A life-size robot named “Mark 1”, built by product and graphic designer Ricky Ma, 42, is seen in Hong Kong, China March 31, 2016. Ma, a robot enthusiast, spent a year-and-a half and more than HK$400,000 ($51,000) to create the humanoid robot, which is modelled after a Hollywood star, to fulfil his childhood dream. The eyes of the robot include face and color tracking functions. (Photo by Bobby Yip/Reuters)

Dancers perform on their way to attend a rally with former President Luiz Inacio Lula da Silva, “Lula”, supporting President Dilma Rousseff in the historic Lapa neighborhood on April 11, 2016 in Rio de Janeiro, Brazil. Brazil's congressional impeachment committee approved the motion to proceed with President Dilma Rousseff's impeachment process today. A full vote by the lower house of Congress on the impeachment is scheduled for Sunday to decide whether she will face trial. (Photo by Mario Tama/Getty Images)

Supporters of former Haitian President Jean-Bertrand Aristide dance and drum as they wait near the airport for his expected arrival from Cuba, where he underwent medical treatment, in Port-au-Prince, Haiti, Friday, July 16, 2021. Aristide's return adds a potentially volatile element to an already tense situation in a country facing a power vacuum following the July 7 assassination of President Jovenel Moïse. (Photo by Fernando Llano/AP Photo)

A giant classic Hindu Ramayana statue dons a face mask to remind passengers to keep to coronavirus precautions at the Suvarnabhumi airport in Bangkok, Thailand, Wednesday, July 21, 2021. The Civil Aviation Authority of Thailand has ordered a halt to all domestic flights operating from the most severely affected provinces effective Wednesday. Exceptions are allowed for flights to destinations that are part of a plan that allows vaccinated travelers from abroad to stay for two weeks on popular islands such as Phuket and Samui without quarantine confinement. (Photo by Sakchai Lalit/AP Photo)

Men play cricket in Kabul, Afghanistan, 16 September 2021. A humanitarian crisis and alleged widespread human rights violations are among the top challenges Afghanistan faces a month after the Taliban's lightning-fast capture of Kabul. The economic crisis threatened to push 97 percent of the 40 million people into poverty by mid-2022, the United Nations has warned. (Photo by EPA/EFE/Stringer)