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 n, temp, ans;
	scanf("%d",&n);
	temp = n; ans = 0;
	while (temp > 0){
		ans += temp % 10;
		temp /= 10;
	}
	if (ans == 1) ans = 10;
	printf("%d\n",ans);
	return 0;
}