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