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![LeetCode 1604. [Medium] Alert Using Same Key-Card Three or More Times in a One Hour Period](/_next/image?url=https%3A%2F%2Fi.ytimg.com%2Fvi%2FamjKpu3wHKk%2Fhqdefault.jpg%3Fsqp%3D-oaymwEjCOADEI4CSFryq4qpAxUIARUAAAAAGAElAADIQj0AgKJDeAE%3D%26rs%3DAOn4CLC2RfSUXmoTIeoDygnOb9xf7Pg3pA&w=256&q=75)