import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        long r = sc.nextLong();
        long min = 2018;
        r = Math.min(r, Math.min(r, l + 2019));
        for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        }
        System.out.println(min);
    }

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

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        long r = sc.nextLong();
        long min = 2018;
        r = Math.min(r, Math.min(r, l + 2019));
        for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        }
        System.out.println(min);
    }

} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        long r = sc.nextLong();
        long min = 2018;
        r = Math.min(r, Math.min(r, l + 2019));
        for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        }
        System.out.println(min);
    } main {
        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        long r = sc.nextLong();
        long min = 2018;
        r = Math.min(r, Math.min(r, l + 2019));
        for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        }
        System.out.println(min);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long l = sc.nextLong(); l sc.nextLong() sc.nextLong sc long r = sc.nextLong(); r sc.nextLong() sc.nextLong sc long min = 2018; min 2018 r = Math.min(r, Math.min(r, l + 2019)) r Math.min(r, Math.min(r, l + 2019)) Math.min Math r Math.min(r, l + 2019) Math.min Math r l + 2019 l 2019 for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        } long i = l; long i = l; i l i < r i r i++ i++ i {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        } {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        } for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            } long j = i + 1; long j = i + 1; j i + 1 i 1 j <= r j r j++ j++ j {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            } {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            } if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                } i % 2019 == 0 i % 2019 i 2019 0 {
                    System.out.println(0);
                    return;
                } System.out.println(0) System.out.println System.out System System.out 0 return; min = Math.min(min, (i * j) % 2019) min Math.min(min, (i * j) % 2019) Math.min Math min (i * j) % 2019 (i * j) i j 2019 System.out.println(min) System.out.println System.out System System.out min String[] args args public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        long r = sc.nextLong();
        long min = 2018;
        r = Math.min(r, Math.min(r, l + 2019));
        for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        }
        System.out.println(min);
    }

} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        long r = sc.nextLong();
        long min = 2018;
        r = Math.min(r, Math.min(r, l + 2019));
        for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        }
        System.out.println(min);
    }

} Main
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        long r = sc.nextLong();
        long min = 2018;
        r = Math.min(r, Math.min(r, l + 2019));
        for (long i = l; i < r; i++) {
            for (long j = i + 1; j <= r; j++) {
                if (i % 2019 == 0) {
                    System.out.println(0);
                    return;
                }
                min = Math.min(min, (i * j) % 2019);
            }
        }
        System.out.println(min);
    }

}
