Total of the first n orders

Problem

An online store numbers its orders 1, 2, 3 and so on. A report needs the sum of the first n order numbers.

Given n, print 1 + 2 + ... + n.

Example

Input

Output

1 + 2 + 3 + 4 = 10.

Try the problem first. Open one hint at a time.

Hint 1

Use a variable that starts at 0 and collects the total.

Hint 2

Add each number from 1 to n. The stop value of range is not included.

Write your Python code, run it on the examples and submit it to hidden tests.