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 C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int main(){
    int N;
    int A, B, i;
    int min=100000000, ans=0;

    scanf("%d", &N);
    for(i=1; i<(N+1)/2; i++){
        A=i;
        B=N-i;
        ans=0;
        while(A>0){
            ans+=A%10;
            A = A/10;
        }
        while(B>0){
            ans+= B%10;
            B=B/10;
        }
        
        if(ans<min){
            min = ans;
        }
    }

    printf("%d", min);

    return 0;
}