Problem:
Score : 200 points

Problem Statement

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".

Sample Input 1

15

Sample Output 1

6

When A=2 and B=13, the sums of their digits are 2 and 4, which minimizes the value in question.

Sample Input 2

100000

Sample Output 2

10

Solution in JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

function main(input) {
    var array = input.split('');
    var sum = 0;

    for(var i = 0; i< array.length; i++){
        sum += parseInt(array[i], 10);
    }
    if(sum ==1) console.log(10);
    else console.log(sum);
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));