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>

int main()
{
	int N,ans=0,n,i;
	scanf("%d",&N);
	for(i=0; N>0; i++){
		ans+=N%10;
		N=N/10;
	}
	if(ans==1)
		ans=10;
	printf("%d\n",ans);
	return 0;
}
