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 = Integer.MAX_VALUE;
        for (int i = 1; i < n; i++) {
            int tmpA = i;
            int tmpB = n - tmpA;

            int tmpSum = digitsSum(tmpA) + digitsSum(tmpB);
            if (ans > tmpSum) ans = tmpSum;
        }

        System.out.println(ans);
    }

    private static int digitsSum(int num) {
        int ans = 0;
        while (num > 0) {
            ans = ans + (num % 10);
            num /= 10;
        }

        return ans;
    }
}
