A. Crystal Ball Sequencetime limit per test2 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard outputCrystal 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.InputThe only line of input contains an integer n (0 ≤ n ≤ 9).OutputOutput the n-th element of crystal ball sequence.ExamplesInput1Output7Input3Output37
Input1
Output7
['*special problem', 'implementation', '*1400']