e-olymp
Problems

Match’s model

Match’s model

prb3

Samodelkin, Professor decided make by hand volumetric model bricks from matches, and use the matches for edges. Length of edges of every brick equally for one match.

For model’s construction of three bricks he uses 28 matches.

What least quantity of matches Samodelkin needs for construction of model with N bricks?

Every number of problems does not exceed 2·109.

Input

One number N is quantity of bricks.

Output

One number is quantity of matches.

Time limit 1 second
Memory limit 128 MiB
Input example #1
3
Output example #1
28
Author Жуковский С. С.
Source Житомирская областная олимпиада