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<bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[])
{
	int n,ans =0;
	cin>>n;
	while (n>0)
	{
		ans+=n%10;
		n/=10;
	}
	if (ans==1)
	{
		ans+=9;
	}
	printf("%d\n",ans );
	return 0;
}