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 Kotlin (1.0.0) (judge verdict: Accepted)

import java.util.*;
fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val L = sc.nextLong()
    val R = sc.nextLong()
    
    if(R-L>2019){
        println(0);
    }
    else{
    	var ans:Long=2000000000000000000
        for(i in L..R){
            for(j in i+1..R){
                var tmp:Long=i*j
                ans=Math.min(tmp%2019,ans)
            }
        }
        println(ans)
    }
}