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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.util.*;
class Main {

    static Scanner scan = new Scanner(System.in);
    public static void main(String[] args) {
            int N = scan.nextInt();
            int change  = Integer.MIN_VALUE;
           if(N % 1000 == 0) {
               change = 0;
           } else {
                int rem = N / 1000;
                change = (rem + 1) * 1000 - N;
            }
            System.out.println(change);
    }
}