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)

import java.util.*

fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val l = sc.nextLong()
    val r = sc.nextLong()
    println(problem133c(l, r))
}

fun problem133c(l: Long, r: Long): Long {
    var min = Long.MAX_VALUE
    var l = l % 2019
    var r = r % 2019
    for (i in l..r) {
        for (j in i+1..r) {
            min = Math.min(min, (i * j) % 2019)
        }
    }
    if (min == Long.MAX_VALUE) min = 0
    return min
}