You have 12 liter jug, 8 liter jug, 5 liter jug. 12 liter jug have full of water.
Your goal is finally the 12 liter and 8 liter jug contains 6 liter water and 5 liter jug contains no water. You have only 12 liter water and you are not getting more water from any other resources.
How can you fill the water?