Problem:
Score : 300 points

Problem Statement

You are given two non-negative integers L and R.
We will choose two integers i and j such that L \leq i < j \leq R.
Find the minimum possible value of (i \times j) \mbox{ mod } 2019.

Constraints

All values in input are integers.

0 \leq L < R \leq 2 \times 10^9

Input

Input is given from Standard Input in the following format:

L R

Output

Print the minimum possible value of (i \times j) \mbox{ mod } 2019 when i and j are chosen under the given condition.

Sample Input 1

2020 2040

Sample Output 1

2

When (i, j) = (2020, 2021), (i \times j) \mbox{ mod } 2019 = 2.

Sample Input 2

4 5

Sample Output 2

20

We have only one choice: (i, j) = (4, 5).

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		int L = Integer.parseInt(sc.next());
		int R = Integer.parseInt(sc.next());
		int ans = 2019;

		if (L + 2019 < R) {
			R = L + 2019;
		}

		int i;
		int j;
		int mod;
		for (i = L; i <= R-1; i++) {
			for (j = i + 1; j <= R; j++) {
				mod = ((i % 2019) * (j % 2019)) % 2019;
				if (mod < ans) {
					ans = mod;
				}
			}

		}

		System.out.println(ans);

	}

}