#P162A. Pentagonal numbers
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ID: 2320
Type: RemoteJudge
3000ms
256MiB
Tried: 0
Accepted: 0
Difficulty: (None)
Uploaded By:
Hydro
Tags> Pentagonal numbers
No submission language available for this problem.
Description
Pentagonal numbers are figurate numbers which can be calculated using the formula pn = (3n2 - n) / 2 (always integer). You are given n; calculate n-th pentagonal number.
The only line of input contains an integer n (1 ≤ n ≤ 100).
Output the n-th pentagonal number.
Input
The only line of input contains an integer n (1 ≤ n ≤ 100).
Output
Output the n-th pentagonal number.
Samples
2
5
5
35