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 (1.3.71) (judge verdict: Wrong Answer)

import java.util.*

fun main(args: Array<String>) {
  val sc = Scanner(System.`in`)
  val l = sc.nextLong()
  val r = sc.nextLong()

  var ans = 2019L
  for (i in l..r) {
    for (j in l+1L..r) {
      val ij = i * j
      val tmp = ij % 2019L
      if (tmp == 0L) {
        println(0)
        return
      }
      if (tmp < ans) {
        ans = tmp
      }

    }
  }
  println(ans)
}