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