Villagers look on as Mount Sinabung volcano spews thick volcanic ash, as seen from Beganding village in Karo, North Sumatra province, on May 19, 2017. Sinabung roared back to life in 2010 for the first time in 400 years. After another period of inactivity, it erupted once more in 2013 and has remained highly active since. (Photo by Ivan Damanik/AFP Photo)

Russians play accordions as they walk near the building of the Federal Security Service (FSB, Soviet KGB successor) in Lubyanskaya Square to mark May Day in Moscow, Russia, Sunday, May 1, 2016. As in Soviet times, about one hundred thousand of cheerful workers paraded across Red Square despite a chilly rain, but instead of red flags with the Communist hammer and sickle, they waved the blue flags of the dominant Kremlin party and the Russian tricolor. (Photo by Alexander Zemlianichenko/AP Photo)

A visitor looks at a sculpture by a Chinese artist Chen Wenling at the "Sculpture by the Sea" exhibition which runs along the Bondi to Tamarama coastal walk in Sydney on October 22, 2015. The world's largest annual free-to-the-public outdoor sculpture exhibition runs from October 22 – November 8 this year and features over 107 sculptures by artists around the world. (Photo by Saeed Khan/AFP Photo)

Crowds watch surfers as the first big swell of the year arrives in Nazaré, Portugal on October 28, 2015. (Photo by Pedro Miranda/Demotix/Corbis)

The British rock and roll group the Beatles talk to Ed Sullivan at CBS Studio 50 before their live television appearance on “The Ed Sullivan Show” in New York, February 10, 1964. From left to right are, Sullivan, John Lennon, Ringo Starr, holding a cigarette, and Paul McCartney. (Photo by AP Photo)

A Vietnamese woman, wearing the traditional “ao dai” long dress, poses for photos along peach blossom flowers ahead of the Vietnamese “Tet” (Lunar New Year festival), in a field in Hanoi, Vietnam, February 2, 2016. (Photo by Reuters/Kham)

In this January 23, 2015 photo, Guillermo Luna Martinez, 36, carries freshly painted piñatas representing Disney's Frozen snowman character Olaf downstairs to where his wife Elvia Vicente Albarran will use paper to craft the character's eyes, teeth, and distinctive tuft of hair, at the family's workshop in the Iztapalapa neighborhood of Mexico City. Though Luna and his wife have chosen to work in the family business, they plan to let their children, Guillermo, 10, and Melissa, 9, decide for themselves. “Who knows if the business will last forever”, said Luna, “I'd prefer that they study and get a career, for them to have a better future”. (Photo by Rebecca Blackwell/AP Photo)

Indian Air Force soldiers toss their rifles as they perform during the full-dress rehearsal for Indian Air Force Day at the Hindon air force station on the outskirts of New Delhi October 6, 2015. (Photo by Anindito Mukherjee/Reuters)