Problem:
Score : 200 points

Problem Statement

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".

Sample Input 1

15

Sample Output 1

6

When A=2 and B=13, the sums of their digits are 2 and 4, which minimizes the value in question.

Sample Input 2

100000

Sample Output 2

10

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();

        int min = Integer.MAX_VALUE;
        for (int x = 1; x <= n; x++) {
            int y = n - x;
            if (y <= 0) continue;

            int tmpMin = sumDigits(x) + sumDigits(y);
            if (tmpMin < min) min = tmpMin;
        }

        System.out.println(min);
    }

    private static int sumDigits(int number) {
        int sum = 0;

        while (number > 0) {
            sum = sum + (number % 10);
            number /= 10;
        }

        return sum;
    }
}