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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <stdio.h>

int main(void){
    int n;
    int a=1, b;
    int i, temp, ans=1000000;
    scanf("%d", &n);
    
    for(i=a; i<n; i++){
        b = n-i;
        temp += i/100000;
        temp += i/10000%10;
        temp += i/1000%10;
        temp += i/100%10;
        temp += i/10%10;
        temp += i%10;
        temp += b/100000;
        temp += b/10000%10;
        temp += b/1000%10;
        temp += b/100%10;
        temp += b/10%10;
        temp += b%10;
        
        if(ans >= temp){
            ans = temp;
        }
    }
    printf("%d\n", ans);
    
    return 0;
}