fun main(args: Array<String>){
    val (l, r) = readLine()!!.split(" ").map { it.toInt() }
    val a = l % 2019
    val b = r % 2019
    var min = 2019
    if (r - l > 2019) min = 0
    if (a < b) {
        for (i in a until b+1) {
            if (b - a == 1) {
                min = a * b % 2019
                break
            }
            for (j in i + 1 until b+1) {
                val x = i * j
                val modX = x % 2019
                if (min > modX) min = modX
            }
        }
    } else {
        for (i in b until a+1) {
            if (a - b == 1) {
                min = a * b % 2019
                break
            }
            for (j in i + 1 until a+1) {
                val x = i * j
                val modX = x % 2019
                if (min > modX) min = modX
            }
        }
    }
    println(min)
}