Joana and the Odd Numbers

Joana loves playing with odd numbers. In the other day, she started writing, in each line, an odd number of odd numbers. It looked as follows: 1 357 9 11 13 15 17 19 21 23 25 27 29 31 ... On a certain line Joana wrote 55 odd numbers. Can you discover the sum of the last three numbers written in that line? Can you do this more generally for a given quantity of odd numbers? Given the number N of odd numbers in a certain line, your task is to determine the sum of the last three numbers of that line. Input The input is a sequence of lines, one odd number N (1 < N < 1000000000) per line Output For each input line write the sum of the last three odd numbers written by Joana in that line with N numbers. This sum is guaranteed to be less than 263. Sample Input 3 5 7 Sample Output 15 45 87