Description

When traveling by plane, if a passenger's luggage weighs less than or equal to 20 kilograms, the fee is 1.68 yuan per kilogram. If the luggage weighs more than 20 kilograms, the fee is 1.98 yuan per kilogram. Write a program to calculate the fee (rounded to 2 decimal places).

Input Format

The weight of the luggage.

Output Format

The fee (rounded to 2 decimal places).

Sample

20.00

33.60