## A Sum Problem

This is a sample problem to demonstrate the runtimes of different solutions with different time complexities.

Calculate the sum of integers in the range \([1, N]\).

#### Input Specification

The first line of the input will contain an integer \(N\) \((1 \le N \le 10^9)\).

#### Output Specification

Output the sum of integers in the range \([1, N]\). For C++ and Java users make sure you use `long long`

or `long`

to prevent integer overflow.

#### Sample Input

`4`

#### Sample Output

`10`

#### Sample Explanation

The sum is \(1 + 2 + 3 + 4 = 10\).

## Comments