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: Wrong Answer)

fun main(args: Array<String>) {
  var split = readLine()!!.split(" ")
  val L = split[0].toLong()!!
  val R = split[1].toLong()!!
  val a = L / 2019
  val b = R / 2019
  val am = L % 2019
  val bm = R % 2019
  if (a == b) {
    val i = L
    val j = L + 1
    val result = (i % 2019 * j % 2019)
    println(result)
  } else {
    println(0)
  }
}