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 <bits/stdc++.h>
using namespace std;

int main() {
  int a,b,c=0;
  cin>>a;
  b=a;
  c+=a%10;
  while(a>=10){
    a=a/10;
    c+=a%10;
  }
  if(c==1&&b>1){
    cout<<10<<endl;
  }
  else{
    cout<<c<<endl;
  }
}