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.*;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N=sc.nextInt();
        int min=999999999;
        for(int a=1;a<=N/2;a++){
            int A = a;
            int B = N-a;
            int sum=0;
            while(A!=0){
                sum+=A%10;
                A/=10;
            }
            while(B!=0){
                sum += B%10;
                B/=10;
            }
            if(min>sum) min = sum;
        }
        System.out.println(min);
    }
}