Sum of Digits of N
Add the decimal digits of a number recursively.
Input format
A single line with one integer N (N >= 0).
Output format
Print the sum of the decimal digits of N.
Constraints
- Values fit in a 64-bit signed integer
- Trailing whitespace and a trailing newline are ignored by the judge
Read from stdin, write to stdout. Sample cases below show the exact format.
Sample cases
Example 1
Input
0Expected output
0Example 2
Input
5Expected output
5