Total of the first n orders

Problem

A report adds the order numbers 1 to n. Write a recursive function total_to(n) that returns 1 + 2 + ... + n, read n, and print the result.

Example

Input

Output

1 + 2 + 3 + 4.

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

Hint 1

The base case is n = 0, which gives 0.

Hint 2

Otherwise return n plus the total of n - 1.

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