Migrants ride on top of a northern bound train toward the US-Mexico border in Juchitan, southern Mexico, Monday, April 29, 2013. Migrants crossing Mexico to get to the U.S. have increasingly become targets of criminal gangs who kidnap them to obtain ransom money. (Photo by Eduardo Verdugo/AP Photo)

A girl jumps to touch cherry blossoms in full bloom in Fussa, outskirts Tokyo, Japan, 05 April 2014. Temperatures being very constant made blossoms to keep full bloom for holiday makers. (Photo by Kimimasa Mayama/EPA)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)

Corporal of Horse Andy Radford prepares to mount his horse in the parade square at Hyde Park Barracks on April 15, 2011 in London, England. Members of the Household Cavalry gave a behind the scenes tour of many of the duties performed as part of their daily routine, including special preparation ahead of the forthcoming Royal Wedding. The Household Cavalry will perform several ceremonial duties during the summer, including the Royal Wedding on April 29, and the Queen's Birthday Parade (Trooping the Colour) in June. (Photo by Dan Kitwood/Getty Images)

Volodymyr, a service member of the Ukrainian armed forces, plays with puppies at fighting positions on the line of separation from pro-Russian rebels in Donetsk region, Ukraine on April 10, 2021. The two unnamed puppies living on frontline positions will be taken home and named by soldiers departing on troops rotation. (Photo by Oleksandr Klymenko/Reuters)

Relatives wearing personal protective equipment (PPE) mourn a man, who died from the coronavirus disease (COVID-19), during his funeral at a crematorium in New Delhi, India on April 21, 2021. (Photo by Adnan Abidi/Reuters)

A young woman poses for a selfie at Red Square which is under preparations for the Victory Parade during sunset in Moscow, Russia, Monday, April 26, 2021. Russia will celebrate celebrate 76 years of the victory in WWII on May 9, 2021. (Photo by Alexander Zemlianichenko/AP Photo)

A South Korea university student gets her head shaved during a protest against Japan's decision to release contaminated water from its crippled Fukushima nuclear plant into the sea, in front of the Japanese embassy, in Seoul, South Korea, April 20, 2021. (Photo by Kim Hong-ji/Reuters)