You Must Escape Level 13

You Must Escape Level 13 Walkthrough:
Look at the black board on the left wall and take the stick underneath it.

Look at the telescope and take the stick hidden on it. Also take the water bottle next to the bookshelf in the corner.

Go to the ladder and add the two sticks to the missing steps on the ladder. Tap it and climb to the top.

Take the knife.

You Must Escape Level 13 Walkthrough:Go to the desk and use the knife to get the left lens of the glasses.

Add the lens to the telescope, then zoom in and you will see U.S.A.

Enter "USA" into the top left drawer on the desk. Take the paper and combine it with the water bottle.

Go to the black board and use the wet paper to clean it completely (until you see 5647 and the paper disappears).

Look at the bookshelf next to the door and tap the books in order: 5, 6, 4, 7 - take the screwdriver.

Use the screwdriver on all four screws of the vent underneath the bookshelf with the ladder, then take the key and use it on the door.
Proceed to the next You Must Escape level!

Hit like if the You Must Escape level 13 walkthrough helped you! Thanks :)