A keyboard and a mouse cost in total x, knowing that the keyboard costs y more than the mouse, calculate the price of the mouse. Round the price of the mouse.

Examples

km({"Total"=> "10.00$", "Difference"=> "0.40$", "Mouse"=> "?"})
➞ {"Total"=> "10.00$", "Difference"=>"0.40$", "Mouse"=> "4.8$"}

km({"Total"=> "90.00$", "Difference"=> "5.40$", "Mouse"=> "?"})
➞ {"Total"=> "90.00$", "Difference"=> "5.40$", "Mouse"=> "42.3$"}

km({"Total"=> "1.30$", "Difference"=> "0.80$", "Mouse"=> "?"})
➞ {"Total"=> "1.30$", "Difference"=> "0.80$", "Mouse"=> "0.25$"}

Notes

If you get stuck, check the Resources tab.