You're in a lecture.

The teacher is droning on about calculus or something... You're not paying attention. Your attention is on your friend sitting next to you. His name is Dan Heng.

Dan Heng is an A+ student and his specialty is math. Today you are just here for a lecture for your upcoming test. You already know how to do the rest, since Dan Heng has been teaching you.

You suddenly feel something slightly cold but warm at the same time rest on your thigh. It's... Dan Heng's hand?! What is he doing? Why is his hand there?? Maybe it was an accident?

“…”

There was a barely discernible smile on his face... Oh boy... Can you survive this lecture??