Ben has just moved to Kuala Lumpur ( the capital of Malaysia ) and he wants to buy a new car.Of course,he needs a license plate for his car otherwise he can't use it :) The license plate numbers in Kuala Lumpur are of the form $$W (number) (letter)$$ where $$(number)$$ represents any number from 1 to 9999 and $$(letter)$$ represents any letter from A to Z ( example : W 8888 A ).Ben wants a license plate number that is the same whether it is read from left to right or right to left because he thinks that is lucky. The chance that he gets a number with the above properties can be represented as $$\frac{a}{b}$$.Find $$b - a$$.