Demonstrators wear masks depicting Brazil's former president Luiz Inacio Lula da Silva (R) and Brazil's President Dilma Rousseff (L) as they take part in a protest calling for the impeachment of Rousseff at Paulista Avenue in Sao Paulo, Brazil, December 13, 2015. (Photo by Nacho Doce/Reuters)

Refugees disembark and make their way to a camp at a hotel touted as the world's most northerly ski resort in Riksgransen, Sweden, December 15, 2015. (Photo by Ints Kalnins/Reuters)

A displaced Iraqi boy leads his animals to safety after escaping from Islamic State controlled village of Abu Jarboa during clashes with IS militants near Mosul, Iraq November 1, 2016. (Photo by Ahmed Jadallah/Reuters)

A leaflet denouncing South Korean President Park Geun-hye lies on the ground after it was torn at a protest calling Park to step down, in Seoul, South Korea, November 19, 2016. (Photo by Kim Hong-Ji/Reuters)

A woman smokes a cigar as she reads the newspaper in a street of Havana, on November 26, 2016, the day after Cuban revolutionary leader Fidel Castro died aged 90. One of the world's longest-serving rulers and modern history's most singular characters, Castro defied 11 US administrations and hundreds of assassination attempts. (Photo by Yamil Lage/AFP Photo)

A visitor watches the exhibit “Enchanted: Forest of Light” at Descanso Gardens in La Canada Flintridge, California U.S., December 9, 2016. (Photo by Mario Anzuoni/Reuters)

An opposition fighter from the Failaq al-Rahman brigade fires a heavy machine gun in Jobar, a rebel-held district on the eastern outskirts of the Syrian capital Damascus, on March 19, 2017. (Photo by Amer Almohibany/AFP Photo)

A reveller catches beer thrown from a balcony during the opening day or “Chupinazo” of the San Fermin Running of the Bulls fiesta on July 6, 2017 in Pamplona, Spain. The annual Fiesta de San Fermin, made famous by the 1926 novel of US writer Ernest Hemmingway entitled “The Sun Also Rises”, involves the daily running of the bulls through the historic heart of Pamplona to the bull ring. (Photo by Pablo Blazquez Dominguez/Getty Images)