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.stream.Stream;

public class Main {
    public static void main(final String[] args) {
        final java.util.Scanner scanner = new java.util.Scanner(System.in);
        final String line = scanner.nextLine();

        if (line.matches("10+")) {
            System.out.println("10");
        } else {
            final int sum = Stream.of(line.split("")).mapToInt(Integer::valueOf).sum();
            System.out.println(sum);
        }
    }
}