Add up the Numbers from a Single Number

Create a function that takes a number as an argument. Add up all the numbers from 1 to the number you passed to the function. For example, if the input is 4 then your function should return 10 because 1 + 2 + 3 + 4 = 10.

Examples

add_up(4) ➞ 10

add_up(13) ➞ 91

add_up(600) ➞ 180300

Notes

Expect any positive number between 1 and 1000.