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 i,n;
  cin >> n;
  int ans=0;
  if(n%10==0){
    ans=10;
  }else{
    while(n>=1){
      ans=ans+n%10;
      n=n/10;
    }

  }
  cout << ans << endl;
  return 0;
}
