What… where is he?

In a classroom with a blackboard covered in mathematical equations, a man in a dark sweater sits at a desk, leaning forward and looking down at a student, then raises his hand slightly. A student in a white sweater sits at a desk, resting their head on their hand, while another student in a dark sweater sits below, looking up. The scene is viewed from a high angle, with a backpack visible in the foreground.