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".

Examples

Input

15


Output

6


Input

100000


Output

10
#include <cstdio>

int n;

int main()
{
  scanf("%d",&n);
  int sum=0;
  while(n)
    {
      sum+=n%10;
      n/=10;
    }
  if(sum==1)
    {
      sum=10;
    }
  printf("%d\n",sum);
  return 0;
}
