A demonstrator throw a firebomb during clashes with Turkish riot police officers in Istanbul, Turkey, Friday, May 1, 2015. The government assigned 30,000 police officers backed by helicopters as workers and demonstrators determined to defy a government ban, tried to march to iconic Taksim Square, where 35 people were killed during May Day celebration in 1977. (Photo by Emrah Gurel/AP Photo)

Men and Women dressed as zombies walk through Hyde Park on February 25, 2012 in Sydney, Australia. The annual Zombie Walk raises money for the Brain Foundation and this year teamed up with FX channel in promotion of “The Walking Dead” series premiering in Australia this weekend. (Photo by Brendon Thorne/Getty Images)

Israelis participate in a “Zombie Walk” during the Jewish holiday of Purim on March 6, 2012 in Tel Aviv, Israel. The carnival-like Purim holiday is celebrated with parades and costume parties to commemorate the deliverance of the Jewish people from a plot to exterminate them in the ancient Persian empire 2,500 years ago, as described in the Book of Esther. (Photo by Uriel Sinai/Getty Images)

Natasha Hastings of U.S. on the starting block before the women's 400 metres heats during the 15th IAAF World Championships at the National Stadium in Beijing, China August 24, 2015. (Photo by Lucy Nicholson/Reuters)

A participant, riding a horse and dressed as a knight, presents flowers to women during an event marking Valentine's Day in central Moscow, Russia, February 14, 2016. (Photo by Maxim Zmeyev/Reuters)

Beloni (34) gives a bath to his son, 6, on a small street in the neighborhood of Cite Vincent, on March 21, 2016 in the commune of Cite Soleil in the Haitian capital Port-au-Prince. World Water Day, marked on March 22, 2016, is an international observance to learn more about water related issues and to take action for sustainable management of freshwater resources. (Photo by Hector Retamal/AFP Photo)

Tiffany Porter of Britain falls after competing in the women's 100 metres hurdles final during the 15th IAAF World Championships at the National Stadium in Beijing, China August 28, 2015. (Photo by David Gray/Reuters)

Second placed Zhang Guowei of China gestures as he celebrates after winning silver in the men's high jump final during the 15th IAAF World Championships at the National Stadium in Beijing, China, August 30, 2015. (Photo by Dylan Martinez/Reuters)