The rising sun illuminates the sky above the spires of a church in Vienna, Austria, November 17, 2015. (Photo by Heinz-Peter Bader/Reuters)

A photographer takes a snapshot of the reflection of balloons as they take off from Balloon fiesta park in Corrales, N.M., near a north diversion channel reservoir Wednesday, October 7, 2015. (Photo by Roberto E. Rosales/Albuquerque Journal via AP Photo)

In this photo taken late Thursday, May 7, 2015, a prison guard, left, and seated inmates cast shadows on a wall while waiting for the beginning of a rock concert by Romanian band Pro Musica, inside the Popa Sapca jail in Timisoara, western Romania. (Photo by Adi Piclisan/AP Photo)

Racegoers in fashionable hats attend Ladies Day at Cheltenham Festival on March 15, 2017 in Cheltenham, England. (Photo by David Davies/PA Wire)

Children attend a war safety awareness class conducted by civil defence members, in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria May 14, 2016. (Photo by Khalil Ashawi/Reuters)

A general view of atmosphere at the annual VOLT Festival in Sopron, 208 kms west of Budapest, Hungary on August 16, 2016. (Photo by Mudra László/Rockstar Photographers)

A member of the Revolutionary Armed Forces of Colombia (FARC) pose for a picture at a camp in the Colombian mountains on February 2005. (Photo by Frank Piasecki Poulsen)

Russia's Ekaterina Birlova casts a shadow on the sand as she serves to Poland during a women's beach volleyball match at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Tuesday, August 9, 2016. (Photo by Marcio Jose Sanchez/AP Photo)