Friend`s study room escape

In this puzzle, you are transported back in the office of friends. They decided to play a cruel joke with you, and locked the door from the outside. In order to surprise them, and get out without a key, you need the maximum uptake. Carefully inspect around and look for items that will help accomplish the mission. On the right, in the cells for the inventory will display all found objects. If necessary, at any time, you can use the Pause button to continue the process later.