An easy to make puzzle that is fun to solve (or watch people try to)

Step 1: O

1)In any CAD software start by creating a 36 x 100mm rectangle

2)Then in the middle of this create a 12 x 36mm rectangle

3)Extrude the profile by 12mm

Step 2: C

1)Start with a copy of the "O" to get the same dimensions

2)Make a 12mm channel through from one side to the centre rectangle

3)Extrude the profile by 12mm

Step 3: Done!

Finished, export the files and upload them to 3D printing software and print! EASY

Since i have no 3D printing facilities (hint) , i made one out of wood which works just as well

To Assemble:

1)Put one of the C's through the middle of the O
2)Put the other C over the end of the O and slide in through the gap of the C
3)Push it all UP! :)

I have include some stl.'s but not sure if they work