Area of the hexagon
Very easy
Execution time limit is 1 second
Runtime memory usage limit is 128 megabytes
Find the area of regular hexagon with side .
Input
One integer L (1 ≤ L ≤ 10^9).
Output
The area S, rounded to the nearest integer.
Examples
Input #1
Answer #1
Submissions 2K
Acceptance rate 30%