A semaphore puzzle that has been playing on a loop atop a California building was finally solved by a software engineer after three years.

July 14 (UPI) -- A semaphore puzzle that has been playing on a loop atop a California building was finally solved by a software engineer after three years.

The puzzle -- a looping animation of four circles in various positions -- has been playing on a loop atop the Adobe headquarters building in downtown San Jose since May 2023.

The San Jose Semaphore, designed by artist Ben Rubin, was finally solved this spring by software engineer Brian Vincent.

Vincent analyzed the patterns and determined they represented a code for colors in the pixels of a digital image -- specifically, a single rose from Sandro Botticelli's famous painting Birth of Venus.

"I want to say that the difficulty level on this puzzle is probably perfect," Vincent said in a video released by Adobe. "In some ways it seems a little bit simple, but at the same time it takes a lot of work and a lot of effort, and it stands for years before anyone solves it."

The puzzle was the third in the San Jose Semaphore series. The first, installed about 20 years ago, turned out to be the full text of Thomas Pynchon's novel The Crying of Lot 49. The second was an audio file of Neil Armstrong saying, "One small step for man, one giant leap for mankind."

Adobe said a new semaphore puzzle will be installed soon, and the first person to solve it will receive a free two-year subscription to Adobe Creative Cloud.