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, ans = 0, tmp;
	scanf("%d", &n), tmp = n;
	while(n) {
		ans += n % 10;
		n /= 10;
	}
	if(tmp % 10 == 0) printf("%d\n", ans * 10);
	else printf("%d\n", ans);
	return 0;
}