import core.bitop;
import std.algorithm;
import std.ascii;
import std.bigint;
import std.conv;
import std.functional;
import std.math;
import std.numeric;
import std.range;
import std.stdio;
import std.string;
import std.random;
import std.typecons;
import std.container;

alias sread = () => readln.chomp();
ulong bignum = 1_000_000_007;
alias Pair = Tuple!(long, "begin", long, "end");

T lread(T = long)()
{
    return readln.chomp.to!T();
}

T[] aryread(T = long)()
{
    return readln.split.to!(T[])();
}

void scan(TList...)(ref TList Args)
{
    auto line = readln.split();
    foreach (i, T; TList)
    {
        T val = line[i].to!(T);
        Args[i] = val;
    }
}

void main()
{
    long l, r;
    scan(l, r);
    l %= 2019;
    r %= 2019;
    if (l < r)
    {
        long minmod = (l * r) % 2019;
        foreach (i; l .. r)
        {
            foreach (j; i + 1 .. r)
            {
                long tmpmod = (i * j) % 2019;
                minmod = min(tmpmod, minmod);
            }
        }
        minmod.writeln();
    }
    else
    {
        writeln(0);
    }
}
