You must have played jigsaw puzzle. Ohh yes everyone does one way or the other. There you had different pieces that could fit only at one place with given shape to give you a drawing or else.
Now this is a Russian riddle where you have to fit in the given blocks into a square. You can rotate them but cannot overlap them to put it into the square. They can touch each other.
Lets give it a try!!!
Use mouse to drag the pieces and Use shift + mouse click to rotate. Go ahead now solve the puzzle.