#P130A. Hexagonal numbers
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ID: 2234
Type: RemoteJudge
2000ms
64MiB
Tried: 0
Accepted: 0
Difficulty: (None)
Uploaded By:
Hydro
Tags> Hexagonal numbers
Description
Hexagonal numbers are figurate numbers which can be calculated using the formula hn = 2n2 - n. You are given n; calculate n-th hexagonal number.
The only line of input contains an integer n (1 ≤ n ≤ 100).
Output the n-th hexagonal number.
Input
The only line of input contains an integer n (1 ≤ n ≤ 100).
Output
Output the n-th hexagonal number.
Samples
2
6
5
45