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>
#include<cstdio>
using namespace std;
int n,ans;
int main(){
	scanf("%d",&n);while (n) ans+=n%10,n=n/10;if (ans==1) printf("%d\n",10); else printf("%d\n",ans);return 0;
}