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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args: Array<String>) {
    val n = readLine()!!.toInt()
    var min = Int.MAX_VALUE
    for (i in 1..(n-1)) {
        val temp = sumDigit(i) + sumDigit(n - i)
        min = Math.min(min,temp)
    }
    println(min)
}

fun sumDigit(num: Int): Int {
    val str = num.toString()
    var sum = 0
    str.forEach { sum += it.toString().toInt() }
    return sum
}