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(){
	unsigned long long a,b,n,z;
	cin>>n;
	if(n%10==0) z=10;
	else if(n<10) z=n;
	else z=n%10+n%100/10+n%1000/100+n%10000/1000+n%100000/10000;
	cout<<z;
	return 0;
}