(CBS) -- When Kaitlyn Lee took an AP computer science two years ago, she was one of two girls in the class.
"That was really intimidating," she tells CBS 2's Irika Sargent.
Kaitlyn and her best friend, Sabrina Chung, decided to do something about it. They started the club "<gir1 c0de>" at Barrington High School.
The numbers for the study group have doubled since last year. That's incredible, considering the club meets at 6:30 a.m. an hour before school even starts.
The morning CBS 2 visited, seniors Lisa Yala and Emily Tokarski were using a card-sorting game to share their knowledge of computer coding.
"It gives you a place where you are not afraid to ask for help," Emily Tokarski says of <gir1 c0de>.
Kristen Lewis is one of their teachers.
"They will be changing the game when they go into the workforce. They are really impressive," she says.
Participants have big dreams linked to computer science.
"I'm really interested in artificial intelligence and the potential to help the medical field," Kaitlynn says.
Emily wants to study aerospace engineering and computer science. Sabrina will minor in computer science.
Kaitlynn and Sabrina say they would like to see girls' coding clubs spread elsewhere, including to younger girls in middle school.
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