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 SugarWater = Tuple!(long, "swater", long, "sugar");

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);
    if(r - l >= 2019)
    {
        writeln(0);
        return;
    }

    long minmod = 2019;
    foreach(i; l .. r)
    {
        foreach(j; i + 1 .. r + 1)
        {
            auto mod = (i * j) % 2019;
            minmod = min(mod, minmod);
        }
    }
    minmod.writeln();
}