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.*;
import java.io.*;

import static java.lang.System.in;

public class Main {
    public static void main(String[] args)throws IOException{
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int ans = Integer.MAX_VALUE;
        for(int i=1;i<=n/2;i++){
            ans = Math.min(ans,help(i)+help(n-i));
        }
        System.out.println(ans);
    }
    public static int help(int p){
        int ans = 0;
        while(p>0){
            ans += p%10;
            p /= 10;
        }
        return ans;
    }
}
