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>
#include <cstring>
#include <algorithm>

using namespace std;

int main(){
	int n, ans; scanf( "%d", &n );
	if( n % 10 == 0 ) return puts( "10" ), 0;
	for( ans = 0; n; n /= 10 ) ans += n % 10;
	printf( "%d\n", ans );
	return 0;
}