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();
        sc.close();

        int[] sum = new int[110000];
        sum[0] = 100000;
        for (int i = 1; i < N; ++i) {
            StringBuilder a = new StringBuilder(Integer.toString(i));
            StringBuilder b = new StringBuilder(Integer.toString(N - i));
            for (int j = 0; j < a.length(); j++) {
                sum[i] += Integer.parseInt(a.substring(j, j + 1));
            }
            for (int j = 0; j < b.length(); j++) {
                sum[i] += Integer.parseInt(b.substring(j, j + 1));
            }
        }

        Arrays.sort(sum);
        for (int i = 0; i < 110000; i++) {
            if (sum[i] != 0) {
                System.out.println(sum[i]);
                break;
            }
        }
    }
}