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) throws Exception {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int min = Integer.MAX_VALUE;
        for (int i = 1; i <= n / 2; i++) {
            min = Math.min(min, getDigitSum(i) + getDigitSum(n - i));
        }
       System.out.println(min);
    }
    
    static int getDigitSum(int x) {
        int ans = 0;
        while (x > 0) {
            ans += x % 10;
            x /= 10;
        }
        return ans;
    }
}
