9. Grandma Wang lives on the 6th floor. One day, the elevator broke down, so Grandma Wang had to climb the stairs from the 1st floor to her home. It takes her 3 minutes to climb each floor, and then she rests for a while. The first rest takes 1 minute, and each subsequent rest is 1 minute longer than the previous one. Grandma Wang took $\qquad$ minutes in total to climb from the 1st floor to the 6th floor.
$25$