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<cstdio>
int f[100010];
int main(){
	int N;scanf("%d",&N);
	for(int i=1;i<=N;i++)f[i]=f[i/10]+i%10;
	int ans=1<<30;
	for(int i=1;i<N;i++)if(f[i]+f[N-i]<ans)ans=f[i]+f[N-i];
	printf("%d\n",ans);
} 