Description

The post office has the following rules for mailing packages: if the package weighs more than 30 kilograms, it cannot be mailed. For packages that can be mailed, a handling fee of 0.2 yuan is charged per package, plus the amount calculated according to the following table based on weight x.

Weight (kg)	Rate (yuan/kg)
$x≤10$	$0.80$
$10< x≤20$	$0.75$
$20< x≤30$	$0.70$

Write a program that takes the package weight as input and outputs the required fee or "Fail" if the package cannot be mailed.

Input Format

Input an integer x representing the package weight in kilograms. ($0< x≤100$)

Output Format

Output the corresponding fee (rounded to 2 decimal places) or "Fail" if the package cannot be mailed.

Sample

7

5.80