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
import java.util.*;
public class Main {
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
int N=Integer.parseInt(sc.next());
int ans=2147483647,digsumi=0,digsumj=0;
for(int i=1;i<N;i++){
int tempi=i,tempj=N-i;
while(tempi>0){
digsumi+=tempi%10;
tempi/=10;
}
while(tempj>0){
digsumj+=tempj%10;
tempj/=10;
}
ans=Math.min(ans, digsumi+digsumj);
digsumi=0;digsumj=0;
}

System.out.println(ans);

}
}