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 n;
  cin>>n;
  if(n%10==0){
    cout<<10<<endl;
  }else{
    string s=to_string(n);
    int ans=0;
    for(int i=0;i<s.size();i++)ans+=s[i]-'0';
    cout<<ans<<endl;
  }
}
