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(void)
{
	int n,m=0;
	cin>>n;
	while(n>0){
		m=m+n%10;
		n=n/10;
	}
	if(m==1) m=m*10;
	cout<<m<<endl;
	return 0;
}