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)

/*
非負整数L、Rが与えられます。
２つの整数i,jをL<=i<j<=Rを満たすように選びます。
(i*J)mod2019の最小値を求めてください。
 */


import java.util.*;

public class Main{
  public static void main(String[]args){
    Scanner sc=new Scanner(System.in);
    while(sc.hasNext()){
      long L=sc.nextLong();
      long R=sc.nextLong();
      long ans=1000000000;
      if(R-L>=2019){
        System.out.println(0);
      }else{
        for(long i=L;i<R;i++){
          for(long j=i+1;j<=R;j++){
            ans=Math.min(ans,(i*j)%2019);
          }
        }
      }
      System.out.println(ans);
    }
  }
}