Problem:
Score : 100 points

Problem Statement

We will buy a product for N yen (the currency of Japan) at a shop.

If we use only 1000-yen bills to pay the price, how much change will we receive?

Assume we use the minimum number of bills required.

Constraints

1 \leq N \leq 10000

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the amount of change as an integer.

Sample Input 1

1900

Sample Output 1

100

We will use two 1000-yen bills to pay the price and receive 100 yen in change.

Sample Input 2

3000

Sample Output 2

0

We can pay the exact price.

Solution in Scala (2.13.1) (judge verdict: Wrong Answer)

import scala.math.floor

object Main extends App {

  def change(input: Int) = {
    var firstInt = 0
    if(input % 1000 == 0) {
      firstInt = floor(input / 1000).toInt
    } else {
      firstInt = floor(input / 1000).toInt + 1
    }
  
    val money = firstInt * 1000
    println(money - input)
  }
}