Triangular Number Summation

Given a positive integer N, compute the sum of the first N natural numbers. The sum can be calculated using the formula: \(S = \frac{N(N+1)}{2}\). Your task is to output the computed sum.

inputFormat

The input consists of a single integer N, which represents the number of terms.

outputFormat

Output the sum of the first N natural numbers.

sample

1

1