RIO DE JANEIRO (AP) — Four mathematicians on Wednesday were awarded this year's Fields Medal, a prestigious award that many describe as the Nobel Prize of mathematics.

Given every four years, the prize goes to mathematicians under 40 and the winners were announced during the International Congress of Mathematicians being held in Rio de Janeiro.

Peter Scholze, a 30-year-old professor at the University of Bonn, was the youngest winner.

"My very first success was winning the regional math Olympiad in Berlin. Since then I've been expecting it to stop somewhere, but it hasn't," the German mathematician said.

The other winners were Caucher Birkar, 40, of the University of Cambridge in England; Alessio Figalli, 34, at the Swiss Federal Institute of Technology in Zurich and Akshay Venkatesh, 36, of the Institute for Advanced Study in Princeton and Stanford University in California.

"I couldn't believe it when I got the email," said Figalli, who had to keep this recognition a secret for months.

Upsetting the celebration, someone stole Birkar's medal after the awards ceremony. Organizers said they were cooperating with authorities to retrieve the prize.

Rio has dealt with crime while hosting international mass events before. During the 2016 Olympics, tourists, foreign officials and journalists faced robberies and attacks.

This was the first time the congress has been held in Latin America, and participants came from all over the world to listen to talks by some of the brightest mathematicians.

"This is a recognition that allows us to showcase math talent in Brazil," said Marcelo Viana, the congress organizer and director of the Institute of Pure and Applied Mathematics in Rio.

At the previous congress, Brazilian mathematician Artur Avila was the first Latin American to win the Fields Medal.

But Viana said there is a need to get young Brazilians more excited about the mathematics.

"We have a paradox of having high-level research, but an education system that isn't as successful," he said. "That is probably related to a lack of scientific and mathematical culture in society."