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.*;

public class Main {
	public static void main(String[] args) throws Exception{
		Scanner scn = new Scanner(System.in);
		int n = scn.nextInt();
      	int a = 0;
      	int b = 0;
      	int num = 0;
      	int min = -1;
		for(int i=1; i<=n/2; i++){
          a = i;
          b = n-i;
          int sum = 0;
          while(a>0){
            sum +=a%10;
            a/=10;
          }
          a = sum;
          sum = 0;
          while(b>0){
            sum +=b%10;
            b/=10;
          }
          b = sum;
          num = a + b;
          if(num<min || min==-1) min = num;
        }
      	System.out.println(min);
	}
}