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();
		if (2019 <= r - l) {
			System.out.println(0);
			return;
		}
		long m = 0;
		long min = 2019l;
		long calc = 0;
		for (long i = l; i < r; i++) {
			m = i * i;
			for (long j = i + 1; j <= r; j++) {
				m += i;
				calc = m % 2019;
				if (calc < min) {
					min = calc;
				}
			}
		}

		System.out.println(min);
	}
}

/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