The following languages are only available languages for the problems from the contest
Surprise Language Round #7:
→ Virtual participation
Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.
Crystal ball sequence on hexagonal lattice is defined as follows: n-th element is the number of lattice points inside a hexagon with (n + 1) points on each side. The formula is Hn = 3·n·(n + 1) + 1. You are given n; calculate n-th element of the sequence.
The only line of input contains an integer n (0 ≤ n ≤ 9).
Output the n-th element of crystal ball sequence.
Codeforces (c) Copyright 2010-2020 Mike Mirzayanov