import java.util.*

fun main(args: Array<String>) {
    val argList = Scanner(System.`in`)


    val firstLine = argList.nextLine().split(" ")
    val l = firstLine[0].toLong()
    val r = firstLine[1].toLong()

    val e = RemainderMinimization2019()
    println(e.execute(l, r))

}

class RemainderMinimization2019 {
    private val r2019 = 2019
    fun execute(l: Long, r: Long): Long {

        val lMod = l % r2019
        val rMod = r % r2019

        if (lMod == 0L || rMod == 0L) return 0

        if (l + (r2019 - lMod)  <= r ) {
            // 2019以上離れている場合、
            // 2019の倍数を選べばよいので、modの最小値は0
            return 0
        }

        var ans: Long = 2018
        for (n in l..r) {
            for (i in n + 1..r) {
                val result = n * i % r2019

                if (result == 0L) return 0

                if (ans > result) {
                    ans = result
                }
            }
        }

        return ans
    }
}