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.PrintWriter;
import java.util.*;

public class Main {

    static String br = System.getProperty("line.separator");
    static Scanner sc  = new Scanner(System.in);

    public static void main(String[] args){
        int N = nextInt();

        int min = 0;
        for(int i=1; i<=N/2; i++){
            int A = i;
            int B = N-i;

            int sum = sumDigits(A)+sumDigits(B);
            if(i == 1) min = sum;
            else min = Math.min(sum, min);
        }

        println(min);
    }

    //各桁の和
    public static int sumDigits(long n) {
        int sum = 0;
        while (n != 0) {
            sum += n % 10;
            n /= 10;
        }
        return sum;//合計を返す
    }

    //最大公約数gcd
    static long gcd (long a, long b) {
        long temp;
        while ((temp = a % b) != 0) {
            a = b;
            b = temp;
        }
        return b;
    }
    //最小公倍数lcm
    static long lcm (long a, long b) {
        long temp;
        long c = a;
        c *= b;
        while((temp = a%b)!=0) {
            a = b;
            b = temp;
        }
        return (c/b);
    }
    static int nextInt(){
        return Integer.parseInt(next());
    }
    static Long nextLong(){
        return Long.parseLong(next());
    }
    static String next(){
        return sc.next();
    }
    static void println(Object o){
        PrintWriter out = new PrintWriter(System.out);
        out.println(o);
        out.flush();
    }
   static void print(Object o){
       PrintWriter out = new PrintWriter(System.out);
       out.print(o);
       out.flush();
    }
}
