Takahashi has two positive integers A and B.

It is known that A plus B equals N. Find the minimum possible value of "the sum of the digits of A" plus "the sum of the digits of B" (in base 10).

Constraints

* 2 ≤ N ≤ 10^5
* N is an integer.

Input

Input is given from Standard Input in the following format:


N


Output

Print the minimum possible value of "the sum of the digits of A" plus "the sum of the digits of B".

Examples

Input

15


Output

6


Input

100000


Output

10
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		Integer aInteger = 0;
		Integer bInteger = 0;
		Integer sum;
		Integer min = Integer.MAX_VALUE;
		Integer digitsSum  = new Integer(scanner.next());

		for(int i = 1; i < digitsSum;i++) {
			sum = 0;
			aInteger = i;
			bInteger = digitsSum - aInteger;
			while(aInteger != 0) {
				sum += aInteger % 10;
				aInteger /= 10;
			}
			while(bInteger != 0) {
				sum += bInteger % 10;
				bInteger /= 10;
			}
			if (min>sum) {
				min = sum;
			}
		}
		System.out.println(min);
		scanner.close();
	}
}