SPOJ in Gyumri

  A non-negative integer is called evil if has an even number of ones in its binary representation. Similarly, a non-negative integer is called odious if has an odd number of ones in its binary representation. Let us write down evil and odious numbers in ascending order.

Number index


1


2


3


4


5


6


7


8


9


10


11


12


13


14


…




Evil number


0


3


5


6


9


10


12


15


17


18


20


23


24


27


…




Odious number


1


2


4


7


8


11


13


14


16


19


21


22


25


26


…




   Let E(n) be the n-th evil number in this list. Similarly, let O(n) be the n-th odious number.
   Write a program to calculate the sum of n-th evil and odious numbers E(n) + O(n) given their index n.
Input
   The input file contains a single integer, n (1 ≤ n ≤ 1000000).
Output
   The output file should contain a single integer, the sum E(n) + O(n).
Example




№


stdin


stdout




1


 1


 1




2


 10


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