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 <iostream>
using namespace std;
int n, mn=1e9;

int f(int p) {
	int s=0;
	for(; p; p/=10) s += p%10;
	return s;
}

int main() {
	cin>>n;
	for(int i=1; i<n; i++) mn = min(mn, f(i) + f(n-i));
	cout<<mn;
	return 0;
}