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.io.*;

 
public class Main {
	  public static void main(String args[])throws IOException
             {
		BufferedReader br =    
		    new BufferedReader(new InputStreamReader(System.in));  
		
		
		    String str1 = br.readLine();
		    int N = Integer.parseInt(str1);
		    
		    if(N%10<= 0)
		    {
		    	System.out.println(10);
		    }
		    else
		    {	
		    	int sum = 0;
		    	
		    do {	sum += N % 10;
		    } while((N/= 10)!= 0);
		    	System.out.println(sum);
		    
		    }
        
		    
        	
             }
}