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<stdio.h>
#include<string.h>
#include<math.h>
#include <stdlib.h>
long n,m,b,x,y;
long a=0;
int main(){
scanf("%ld",&n);
while(1){
b=n%10;
a+=b;
n/=10;
if(n==0)break;
}
if(a==1){printf("10");}
else{printf("%ld",a);}
}