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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
int main()
{
    int n,s,i,j,k,t1,t2;
    s=n;
    scanf("%d",&n);
    for(i=1;i<n;i++)
    {
       j=i;
       k=n-j;
       t1=0;
       while(j)
       {
           t1=t1+j%10;
           j=j/10;
       }
       t2=0;
       while(k)
       {
           t2=t2+k%10;
           k=k/10;
       }
       s=min(s,t1+t2);
    }
    printf("%d\n",s);
    return 0;
}