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: Accepted)

object Main extends App {
  //  val file = new File("targetfile")
  val testdata =
    """
1200"""
// 出力例1
// 3
//   val sc = new java.util.Scanner(testdata)
 val sc = new java.util.Scanner(System.in)

  val _x = sc.nextInt

  if (_x % 1000 > 0) {
    println(1000 - _x % 1000)
  } else {
    println(0)
  }
}