People participate in a pillow fight to mark International Pillow Fight Day in the Heroes' Square, in central Budapest, Hungary, Saturday, April 2, 2016. The Pillow Fight Day attracts tens of thousands people in more than 100 cities all over the World each year. ((Photo by Zoltan Balogh/MTI via AP Photo)

A woman carries a water pump to work on February 11, 2017 in Almolonga, Guatemala. The Mayan town in the western highlands district of Quetzaltenango has surged in prosperity in recent years with high-productivity vegetable farming, exporting much of its excess crops to neighborning El Salvador. (Photo by John Moore/Getty Images)

Female police officers from Istanbul's Motorcycled Police Unit wait to search vehicles during a roadside checkpoint operation on March 7, 2017 in Istanbul, Turkey. The rapid response unit nicknamed Dolphins is used primarily in crime prevention operations and has 25 female officers. 6% of Turkey's 250,000 strong police force are women, March 8 marks International Women's Day. (Photo by Chris McGrath/Getty Images)

Dinosaur robots acting as receptionist greet a hotel employee demonstrating how to check-in to the hotel during a press preview for the newly-opening Henn na Hotel Maihama Tokyo Bay in Urayasu, east of Tokyo, Japan March 15, 2017. The reception desk is handled by robots that speak Japanese, English, Chinese and Korean, as well as porter robots that help guests carry luggage to their rooms. Tasks such as window-cleaning and vacuuming are also handled by robots. Japan's second robot-run hotel Henn na Hotel (“strange hotel” in Japanese) opened on March 15, 2017 as the robot-staffed hotel near Tokyo, operating company H.I.S. Co. said. (Photo by Issei Kato/Reuters)

An Iraqi Army member launches a rocket during the operation to retake Mosul from Daesh terrorists in Jadid neighborhood as the clashes between Iraqi Army and Daesh terrorists continue in Mosul, Iraq on April 2, 2017. (Photo by Hemn Baban/Anadolu Agency/Getty Images)

A staff member sets up a ROBOTLEO robot at the Global Mobile Internet Conference (GMIC) 2017 in Beijing, China April 28, 2017. (Photo by Jason Lee/Reuters)

A woman holds an elderly woman on her back to cross a flooded street after a heavy rain in Shenyang, Liaoning province on July 14, 2017. (Photo by Fred Dufour/AFP Photo)

A winter swimmer, wearing a Santa Claus hat to celebrate the upcoming Christmas, reacts as he plays on a frozen lake at a park in Shenyang, Liaoning province, December 22, 2014. The characters on the hat read: “Shenyang Winter Swimming”. (Photo by Reuters/Stringer)