import java.util.Scanner;

class Main {
    public static void main(final String[] args) {
        Scanner scan = new Scanner(System.in);
        long L = scan.nextLong();
        long R = scan.nextLong();
        int ans = Integer.MAX_VALUE;
        long x = 0;
        if (R - L >= 2019) {
            System.out.println(0);
            System.exit(0);
        }
        for (long i = L; i < R; i++) {
            for (long j = L + 1; j <= R; j++) {
                int m = (int) ((i * j) % 2019);
                ans = Math.min(ans, m);
            }
        }
        System.out.println(ans);
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz