Students from St Andrews University are covered in foam as they take part in the traditional Raisin Weekend in the Lower College Lawn, at St Andrews in Scotland on October 22, 2018. The “raisin weekend” stems from a gift of raisins (now flour and foam) traditionally given by a first year student to their academic “parents” in gratitude for their guidance. (Photo by Russell Cheyne/Reuters)

A South Korean marine in action during their regular drill on Yeonpyeong Island, South Korea November 1, 2018. (Photo by Jeon Heon-Kyun/Pool via Reuters)

The singing group The D-Day Darlings take part in the unveiling ceremony of a permanent war memorial, created by artist and writer Fabian Peake, at St Pancras International railway station in London, Britain, November 8, 2018. (Photo by Peter Nicholls/Reuters)

Sukhoi Su-30SM jet fighters of the Russkiye Vityazi (Russian Knights) aerobatic team perform during a demonstration flight in Krasnoyarsk, Russia October 6, 2018. (Photo by Ilya Naymushin/Reuters)

The Swiss Air Force Patrouille Suisse aerobatic team performs during the men's downhill race at the Alpine Skiing FIS Ski World Cup in Wengen, Switzerland, Saturday, January 19, 2019. (Photo by Anthony Anex/Keystone via AP Photo)

Belarusian ornithologist Vladimir Ivanovski, 72, stands on a tree as he builds an artificial nest for birds of prey from tree branches, in a marsh near the village of Kazyany, Belarus on October 20, 2019. (Photo by Vasily Fedosenko/Reuters)

Carnival revelers perform during the Academicos do Baixo Augustaa carnival “bloco” parade in Sao Paulo, Brazil, Sunday, February 24, 2019. (Photo by Andre Penner/AP Photo)

Revellers take part in the Els Enfarinats festival, in the town of Ibi near Alicante, Spain, Saturday December 28, 2019. For about 200-years the inhabitants of Ibi annually celebrate with a battle using flour, eggs and firecrackers, outside the city town hall. (Photo by Alberto Saiz/AP Photo)