Maximum Light Bulbs On in a Chandelier

You are given an integer N representing the number of rows in a chandelier. The chandelier is designed such that the number of light bulbs that can be turned on is maximized when the bulbs are arranged in a triangular pattern. The total number of light bulbs that can be turned on is given by the formula:

\(\frac{N(N+1)}{2}\)

Your task is to compute this value given N.

Example: When N = 3, the maximum number of light bulbs that can be on is \(\frac{3(3+1)}{2} = 6\).

inputFormat

The input consists of a single integer N provided via stdin.

Constraints: 1 ≤ N ≤ 10⁵ (or possibly larger based on the problem context).

outputFormat

Output a single integer representing the maximum number of light bulbs that can be turned on, computed by the formula:

\(\frac{N(N+1)}{2}\)

The result should be printed to stdout.

## sample

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1