A hospital parking lot charges $4 for the first hour or part thereof, and $2 for each additional hour or part thereof. A weekly pass costs $32 and allows unlimited parking for 7 days. If each visit Johnny makes to the hospital lasts one and a half hours, what is the minimum number of visits for which buying a pass would be less expensive than paying each time? ________ visits would make it less expensive for Johnny to buy a weekly pass.?

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