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 Java (OpenJDK 11.0.6) (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 answer = 10000;
    for (int i = 1; i < n; i++) {
      int a = i;
      int b = n - i;
      int sum1 = 0;
      int sum2 = 0;
      while(a > 0) {
        sum1 += a % 10;
        a /= 10;
      }
      while(b > 0) {
        sum2 += b % 10;
        b /= 10;
      }
      if (sum1 + sum2 < answer) {
        answer = sum1 + sum2;
      }
    }
    System.out.println(answer);
  }
}