Олимпиадный тренинг

Задача 38710. Minimum discount


Mr. Duncan, the manager of Duncan's Toy Chest, donates a certain amount of money to children's funds each year around Christmas.  The amount that goes to charity is always equal to the minimum number, which is divided by 2 and the number of toys sold in a year. Given the number of toys sold per year (N), determine the amount that Mr. Duncan will donate. 

Input
The input is a positive integer N (1<=N<=109).

Imprint
Print a single number - the amount that Mr. Duncan will donate.
 
Examples
# Input Output
1 3 6
2 10 10
3 999999999 1999999998