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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

    public static void main(String[] args) {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        try {
            String str = br.readLine();
            String input[] = str.split(" ");
            int L = Integer.valueOf(input[0]);
            int R = Integer.valueOf(input[1]);
            
            int result = 2018;
          if(R-L >2019){
            R = L+2019;
          }
          if(L >= 2019){
            L %= 2019;
            R %= 2019;
          }
            for(int i = L; i<R; i++) {
				if(i%2019 == 0 || result == 0){
                  result = 0;
                  break;
                }
              for(int j = i+1; j<=R; j++) {
                  int N = i* j;
                    if( N % 2019 < result && N % 2019 > 0 ) {
                        result = N % 2019;
                    } else if(N%2019 == 0){
                      result = N % 2019;
                      break;
                    }
                }
            }
            System.out.println(result);
            
            
        }catch(IOException e) {
            
        }
    }

}