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(){
  int a,i,sum;
  sum = 0;
  cin >> a;
  for(i=0;i<6;i++){
    sum += a%10;
    a = a/10;
  }
  if(sum == 1)
    sum = 10;
  cout << sum << "\n";
  return 0;
}