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;

public class Main {

    public static void main(String[] args) {
        int n;
        try (Scanner cin = new Scanner(System.in)) {
            n = cin.nextInt();
        }
        int minsum = Integer.MAX_VALUE;
        for (int a = 1; a <= n / 2; a++) {
            int min = digitsSum(a) + digitsSum(n-a);
            minsum = Math.min(minsum, min);
        }

        System.out.println(minsum);
    }

    static int digitsSum(int x) {
        int t = x;
        int s = 0;
        while(t > 0) {
            s += t % 10;
            t = t / 10;
        }
        return s;
    }
}
