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<iostream>
using namespace std;

int main(void)
{
  int wa;
  cin>>wa;

  int a=0;
  if(wa==10||wa==100||wa==1000||wa==10000||wa==100000)
  {
    cout<<10;
  }
  else
  {
  while(wa>0)
  {
    a+=wa%10;
    wa/=10;
  }
  cout<<a;
  }

}
