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 scan = new Scanner(System.in);
        long L = scan.nextLong();
        long R = scan.nextLong();
        
        long result = 2018;

        for (long i = L; i < R; i++){
            for (long j = i + 1; j <= R; j++){
                long mod = (i * j) % 2019;
                if(result > mod) result = mod;
                if(result == 0) break;
            }
            if(result == 0) break;
        }

        System.out.println(result);
    }
}