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: Time Limit Exceeded)

import java.util.*;

public class Main{
    public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);

      int L=sc.nextInt();
      int R=sc.nextInt();

      //0 < L <= i < j <= R

      int mod,ii,jj;
      int ans = 2019;

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

      System.out.println(ans);

    }
}