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;
  int a[6];
  for(int i=0;i<6;i++){
    a[i]=N%10;
    N/=10;
  }
  int sum=0;
  for(int i=0;i<6;i++) sum+=a[i];
  if(sum==1) cout<<10<<endl;
  else cout<<sum<<endl;
}