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() {
	int n;
	cin>>n;
	int ans=0;
	if(n==10 or n==100 or n==1000 or n==10000 or n==100000){ans=10;}
	else{
		while(n!=0){
			ans+=n%10;
			n=n/10;
		}
	}
	cout<<ans<<endl;
	return 0;
}