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,a=0;cin>>n;
  if(n==10||n==100||n==1000||n==10000||n==100000)cout<<10<<endl;
  else{
    while(n>0){
      a+=n%10;
      n/=10;
    }
    cout<<a<<endl;
  }
}
      