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>) {
    val (l, r) = readLine()!!.split(' ').map(String::toInt)
    val ml = l % 2019
    val mr = r % 2019
    print(when{
        ml > mr -> 0
        ml == 0 || mr == 0 -> 0
        else -> {
            val ls = (ml..mr).toList()
            ls.indices.flatMap { i -> (i+1 until ls.size).map { j ->
                ls[i] * ls[j] % 2019
            }
            }.min()
        }
    })
}