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.*;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        int min = 100000;

        for (int i=1; i<N; i++) {
            int A = i;
            int B = N - i;
            int AB = Main.calc(A) + Main.calc(B);
            min = min < AB ? min : AB;
        }

        System.out.println(min);
    }

    static int calc(int a) {
        int[] nums = {100000, 10000, 1000, 100, 10, 1};
        int sum = 0;

        for (int num : nums) {
            sum += a / num;
            a = a % num;
        }
        return sum;
    }
}