Never underestimate the smarts of a determined college student.

Tuesday was the first test day of the semester for assistant college professor Reb Beatty and his accounting class at Anne Arundel Community College in Maryland. As always, he let students cram as much information as they could onto a 3x5 notecard.

The problem was—he didn’t specify that cheat sheet had to be 3x5 inches.

“Today a student shows up with this,” Beatty wrote on Facebook.

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He shared a photo of a student concentrating on taking the test, but he probably had every answer he needed right in front of him. His cheat sheet was more like a poster, stretching beyond the top of his desk.

“Sure enough, it is 3x5… feet.”

Numbers and specifics matter. He is taking an accounting class, after all.

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“As precise as I am, apparently I never specified inches and therefore yes, it was allowed,” he continued.

Score one for the college student!

“Well played and lesson learned for me,” Beatty said.

Fellow teachers, beware. The student’s ingenious idea has gone viral. As of Thursday evening, Beatty’s post had been shared more than 10,000 times.

Note: This story has been changed to reflect the student is a male, as noted by the professor in an update to his original post.