import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        sc.close();

        int result = (1000 - (N%1000)) % 1000;

        System.out.println(result);
    }

} import java.util.Scanner; Scanner java.util public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        sc.close();

        int result = (1000 - (N%1000)) % 1000;

        System.out.println(result);
    }

} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        sc.close();

        int result = (1000 - (N%1000)) % 1000;

        System.out.println(result);
    } main {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        sc.close();

        int result = (1000 - (N%1000)) % 1000;

        System.out.println(result);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int N = sc.nextInt(); N sc.nextInt() sc.nextInt sc sc.close() sc.close sc int result = (1000 - (N%1000)) % 1000; result (1000 - (N%1000)) % 1000 (1000 - (N%1000)) 1000 (N%1000) N 1000 1000 System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        sc.close();

        int result = (1000 - (N%1000)) % 1000;

        System.out.println(result);
    }

} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        sc.close();

        int result = (1000 - (N%1000)) % 1000;

        System.out.println(result);
    }

} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int N = sc.nextInt();
        sc.close();

        int result = (1000 - (N%1000)) % 1000;

        System.out.println(result);
    }

}