Currently, evaluating the significance of license plates, phone numbers, birth dates, or any sequence of digits is of interest to many people. The way to assess the beauty of a sequence of numbers is as follows: Calculate the sum of the digits in the sequence. If the sum is a single-digit number, that is the beauty value (beauty score) of the sequence. Otherwise, continue calculating the sum of the digits until you get a single-digit number.

Example:

• For the birth date sequence 02022020, the sum of the digits is 8, so the beauty score of the sequence is 8.
• For the phone number 0912345678, the sum of the digits is 45. Continuing to calculate the sum gives 9, so the beauty score of the sequence is 9.

Requirement:

• Given a sequence with ~ n~ digits, evaluate the beauty score of the given sequence.

Input

• Contains a sequence with ~ n ~ digits (~ n \leq 10^5 ~).

Output

• An integer representing the beauty score of the sequence.

Sample Input

02022020

Sample Output

8