In this Friday, February 27, 2015 photo, an Israeli high-school senior preparing to join the Israeli military later this year participates in a privately run training camp for military combat fitness near Yakum, central Israel. With a mandatory three-year military service looming after graduation, teenage boys, and increasingly girls too, are gearing up for the draft, getting into shape and trying to improve their chances of acceptance into elite combat units. (Photo by Oded Balilty/AP Photo)

A woman reacts as she attends a funeral ceremony for Mykola Kuliba and Serhiy Baula, servicemen from the “Aydar” battalion, who were killed in the fighting in eastern Ukraine, at Independence Square in central Kiev, Ukraine, May 26, 2016. (Photo by Gleb Garanich/Reuters)

An Indian Hindu widow smeared with colors sits and watches others playing during Holi celebrations at the Gopinath temple, 180 kilometres (112 miles) south-east of New Delhi, India Monday, March 21, 2016. A few years ago this joyful celebration was forbidden for Hindu widows. Like hundreds of thousands of observant Hindu women they would have been expected to live out their days in quiet worship, dressed only in white, their very presence being considered inauspicious for all religious festivities. (Photo by Manish Swarup/AP Photo)

Students from the University of St Andrews jump into The North Sea, as a good luck tradition before exams start on the East Sands in St Andrews, Fife, Scotland on May 1, 2018. (Photo by Derek Allan/Alamy Live News)

Members of a Chinese opera take a selfie before a performance at a shopping mall ahead of the Chinese Lunar New Year celebrations in Bangkok, Thailand, February 4, 2016. (Photo by Athit Perawongmetha/Reuters)

A Russian Sukhoi Su-25 fighter jet takes off during the withdrawal of Russian troops from Syria at Hmeymim airbase, Syria, March 16, 2016. (Photo by Vadim Grishankin/Reuters/Russian Ministry of Defence)

A Nepalese Gurung community woman, wearing traditional attire, prepares to participate in a parade to mark their New Year known as “Tamu Loshar” in Kathmandu, Nepal, Friday, December 30, 2016. The indigenous Gurungs, also known as Tamu, are celebrating the advent of the year of the bird. (Photo by Niranjan Shrestha/AP Photo)

Performers re-enact the 1947 massacre of Taiwanese intellectuals by mainland China's Nationalists troops during the inauguration ceremony of Taiwan's President Tsai Ing-wen in Taipei, Taiwan, Friday, May 20, 2016. Taiwan inaugurated Tsai as its first female president on Friday, returning the pro-independence Democratic Progressive Party to power amid new concerns over increasingly fractious relations with Beijing and a flagging economy. (Photo by Chiang Ying-ying/AP Photo)