Electricity Bill (Slab Rates)
A (made-up) tariff charges per unit (kWh) in slabs: the first 100 units are free, the next 100 cost ₹4.50 each, the next 200 cost ₹6.00 each, and every unit above 400 costs ₹8.00. Print the bill in rupees with 2 decimals.
Input
The number of units .
Output
The bill.
Constraints
Sample 1
Input
150
Output
225.00
Sample 2
Input
450
Output
2050.00