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)

fun main(args: Array<String>) {
    val sc = java.util.Scanner(System.`in`)
    val L = sc.nextLong()
    val R = sc.nextLong()


    var t = 99999999999L
    (L..Math.min(R - 1, L + 2020)).map { l1 ->
        (Math.max(L + 1, R - 2020)..R).map { r1 ->
            t = Math.min(t, (l1 * r1) % 2019)
        }
    }

    println(t)
}