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 ans = 10000000;
      for(int i=1;i<n;i++){
        int j = n - i;
        int tmp = 0;
        tmp += NumOfDigits(i);
        tmp += NumOfDigits(j);
        if(tmp<ans){
          ans = tmp;
        }
        
      }
      System.out.println(ans);
    }
    public static int NumOfDigits(long num){
    int n = NOfDigits(num);
    int sol = 0;
    for(int i=0;i<n;i++){
      sol += (int)( num / Math.pow(10,n-i-1) );
      num %= (long)Math.pow(10,n-i-1);
    }
    return sol;
  }
  
    public static int NOfDigits(long num){
    int n = 1;
    while(true){
      if( num > Math.pow(10,n) ){
        n++;
      }else{
        break;
      }
    }
    return n;
  }
}