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) {

		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int min = 100001;

		for (int A = 2; A < N; A++) {
			int B = N - A;
			int tmp = calSumOfDigits(A) + calSumOfDigits(B);

			if(tmp < min) {
				min = tmp;
			}
		}
		System.out.println(min);
	}
	//各桁の和を計算
	public static int calSumOfDigits(int n) {
		int sum = 0;
		while(n > 0) {
			sum += n % 10;
			n /= 10;
		}
		return sum;
	}
}