530 - Sum

Sum

Time Limit: 1 sec

**The Problem**

Make a simple program that reads one variable named **N**, Your task is to find the sum of all integer numbers lying between 1 and **N** inclusive.

**The Input**

Input file consist of several lines. Each line contains an integer **N** which is not greater than 100 by its absolute value.

**The Output**

For each line of input, write a single integer number that is the sum of all integer numbers lying between 1 and **N** inclusive. Each output should be in separate line.

**Sample Input**

5

-3

**Sample Output**

15

-5

Problem Setter: Shahin ShamS