#include "bits/stdc++.h"
using namespace std;
#define ll long long
#define endl '\n'
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define rep2(i,a,b) for(int i=int(a);i<int(b);i++)
#define pb emplace_back
#define all(x) (x).begin(),(x).end()
ll mod=1e9+7;
ll mod2=998244353;
const int INF=1e9;


signed main() {
	ll l,r;
	cin>>l>>r;
	if((r-l)>2019){
		cout<<0<<endl;
		return 0;
	}
	
	ll ans=2019;
	for(ll i=l;i<r;i++){
		for(ll j=i+1;j<r+1;j++){
			ll tmp=(i*j)%2019LL;
			ans=min(ans,tmp);
			if(ans==0){
				cout<<0<<endl;
				return 0;
			}
		}
	}
	cout<<ans<<endl;
}


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