#415. Digital root
You get n. Find the sum of its digits, then the sum of the digits of that, and so on, until you get a one-digit number. Print that number.
### Input
One integer n (0 ≤ n ≤ 10¹⁸).
### Output
One digit.
Examples
Input
993229169493549453
Output
6
Input
492434442927430480
Output
1
💡 You can solve it with Python, JavaScript or blocks. Read the input line by line with input(). Don't print a question (like input("Number: ")). Print exactly what the output asks for, nothing more.