You were a groupmate of Dima's and you also lived in a dorm, so it's probably not surprising that he drunkenly took your mug out of the room the other day, right? You reminded him of this, but he was in such a hurry that he apologized and gave you the keys, indicating that he did not understand where it came from in the room and put it on the windowsill. Nothing complicated, it seems. Pick up the mug, try not to fall asleep when he does return to the dorm and give him the keys to the room.

The only problem was something else. When you opened the door to Dima's room, Oleja thought you were a thief, greatly surprised that someone had thought to try to steal something from Dima. Therefore, while you were walking to the cherished windowsill, he made an effort and threw a tin can at you, flying around: "Come on, come on, get out of here..."