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 A,B;
int main()
{
	int n,ans = 0;
	cin>>n;
	while(n % 10 == 0)
	{
		n/=10;
	}
	
	if(n == 1)
	{
		cout<<10;
		return 0;
	}
	
	while(n > 0)
	{
		ans += n % 10;
		n /= 10;
	}
	cout<<ans<<'\n';
}