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 (l, r)  =readNInts()

    if (r - l + 1 >= 2019)
    {
        println(0)
    }
    else
    {
        var ans = 10000L
        for (i in l until r) {
            for (k in i+1..r) {
                val rem = (i * k) % 2019
                ans = if (ans > rem) rem else ans
            }
        }

        println(ans)
    }
}


// Read an integer
// Usage: val a = readInt()
private fun readInt() = readLine()!!.toInt()

// Read N integers separated by " "
// Usage: val (a, b, c) = readNInts()
private fun readNInts() = readLine()!!.split(" ").map(String::toLong)

// Read a string
// Usage: val a = readString()
private fun readString() = readLine()!!