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 sc = new Scanner(System.in);
    int n=sc.nextInt(),min=999999;
    String buffa="",buffb="";
    for(int i=1;i<n;i++) {
    	int a=i,b=n-i,sum=0;
    	buffa=String.valueOf(a);
    	buffb=String.valueOf(b);
    	for(int j=0;j<buffa.length();j++)sum+=Integer.valueOf(buffa.substring(j, j+1));
    	for(int j=0;j<buffb.length();j++)sum+=Integer.valueOf(buffb.substring(j, j+1));
    	min=Math.min(sum, min);
    	//if(sum==1)System.out.println(buffa+"+"+buffb+":"+sum);
    }
    System.out.println(min);
  }
}
