Numeric root
Problem
The digital root of a natural number is obtained as follows. Add up all the digits of the given number. The process is repeated until the result is a single-digit number, which is called the digital root of the number.
Input: The input to the program is a natural number n<=109.
Output: Print its digital root.
Examples
| # |
Input |
Output |
| 1 |
10 |
1 |
| 2 |
888 |
6 |