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 solve(int n){
  if(n%10==0)return 10;
  int res=0;
  while(n){
    res+=n%10;
    n/=10;
  }
  return res;
}

int main(){
  int n;
  cin>>n;
  cout<<solve(n)<<endl;
}
