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![LeetCode 1699: Number of Calls Between Two Persons [SQL]](/_next/image?url=https%3A%2F%2Fi.ytimg.com%2Fvi%2FaTeOVgyuFTA%2Fhq720.jpg%3Fsqp%3D-oaymwEXCNAFEJQDSFryq4qpAwkIARUAAIhCGAE%3D%26rs%3DAOn4CLByRtgr2AwSF0aOvjkk4LlcOgyvjQ&w=256&q=75)
