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
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
int main() {
	int i,sum=0;
	char a[100000];
	scanf("%s", &a);
	for (i = 0; i < 100000; i++) {
		if (a[i] == 0) {
			break;
		}
		sum += a[i] - 48;
	}
	if (sum == 1) {
		sum = 10;
	}
	printf("%d", sum);
}