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: Wrong Answer)

import java.io.*;
class Main{
    public static void main(String[] args) throws Exception{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String sb1 = br.readLine();
        String[] a = sb1.split(" ");
        long[] c = new long[a.length];
        long[] b = new long[a.length];
        long d  = 2019;
        for(int i = 0;i < a.length;i++){
            c[i] = Long.parseLong(a[i]);
        }
        for(int i = 0;i < a.length;i++){
            b[i] = c[i]/d;
        }
        
        if(c[1] < 2019){
            System.out.println(c[0] * (c[0] + 1));
            System.out.println(1);
        } else if(b[0] == b[1]){
            System.out.println((c[0] * (c[0] + 1) %2019));
        }  else {
            System.out.println(0);
        }
        
    }
}