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: Wrong Answer)

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;
    }
}