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;
#define REP(i,n) for (int i=0;i<(n);++i)

int main() {
    string S;cin>>S;
    int sum = 0;
    REP(i,S.size()) sum += S[i]-'0';
    if(sum==1) cout << 10 << endl;
    else cout << sum << endl;
    return 0;
}