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 ans = Integer.MAX_VALUE;
        for (int i = 1; i < n; i++) {
            int tmpA = i;
            int tmpB = n - tmpA;

            int tmpSum = digitsSum(tmpA) + digitsSum(tmpB);
            if (ans > tmpSum) ans = tmpSum;
        }

        System.out.println(ans);
    }

    private static int digitsSum(int num) {
        int ans = 0;
        while (num > 0) {
            ans = ans + (num % 10);
            num /= 10;
        }

        return ans;
    }
}