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 <cstdio>
using namespace std;
int n,m,ans;
int main(){
	scanf("%d",&n);
	m=n;
	while (m){
		ans+=m%10;
		m=m/10;
	}
	if (ans==1 && n%10==0) printf("10"); else printf("%d",ans);
} 