Sum of numbers from 1 to N

C++ Easy loops

Task «Sum of numbers from 1 to N»

Write a program that reads a positive integer N and calculates the sum of all integers from 1 to N inclusive. Use a for loop. It is guaranteed that N does not exceed 1000.

Input Format

One integer N (1 ≤ N ≤ 1000).

Output Format

One integer — the sum from 1 to N.

Examples

Example 1

INPUT

10

OUTPUT

55

Example 2

INPUT

5

OUTPUT

15

main.cpp