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.Scanner;
import java.util.Arrays;

public class Main {

    public static void main(String[] args) {
        new Main().solve();
    }

    void solve() {
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        long ans = Long.MAX_VALUE;
        for (int i = 1; i <= N - 1; i++) {
            int A = N - i;
            ans = Math.min(ans, i / 10000 + i / 1000 % 10 + i / 100 % 10 + i / 10 % 10 + i % 10 + A / 10000 + A / 1000 % 10 + A / 100 % 10 + A / 10 % 10 + A % 10);
        }
        System.out.println(ans);
    }
}