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.*;
public class Main{
  public static int sumOfDigits(int n){
    int sum = 0;
    while(n>0){
      sum+=n%10;
      n/=10;
    }
    return sum;
  }
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    int N = sc.nextInt();
    int ans = Integer.MAX_VALUE;
    for(int i=1;i<N;i++){
      int sumA = sumOfDigits(i);
      int sumB = sumOfDigits(N-i);
      if(ans>sumA+sumB)ans = sumA+sumB;
    }
    System.out.println(ans);
  }
}