import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long L = sc.nextLong();
		long R = sc.nextLong();

		if ( R - L > 2019 ) {
			System.out.println(0);
		} else {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		}
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long L = sc.nextLong();
		long R = sc.nextLong();

		if ( R - L > 2019 ) {
			System.out.println(0);
		} else {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		}
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long L = sc.nextLong();
		long R = sc.nextLong();

		if ( R - L > 2019 ) {
			System.out.println(0);
		} else {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		}
	} main {
		Scanner sc = new Scanner(System.in);
		long L = sc.nextLong();
		long R = sc.nextLong();

		if ( R - L > 2019 ) {
			System.out.println(0);
		} else {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long L = sc.nextLong(); L sc.nextLong() sc.nextLong sc long R = sc.nextLong(); R sc.nextLong() sc.nextLong sc if ( R - L > 2019 ) {
			System.out.println(0);
		} else {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		} R - L > 2019 R - L R L 2019 {
			System.out.println(0);
		} System.out.println(0) System.out.println System.out System System.out 0 {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		} long ans = 2019; ans 2019 for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			} long i = L ; long i = L ; i L i < R i R i++ i++ i {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			} {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			} for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				} long j = i + 1 ; long j = i + 1 ; j i + 1 i 1 j <= R j R j++ j++ j {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				} {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				} long mod = (i * j) % 2019; mod (i * j) % 2019 (i * j) i j 2019 if ( ans > mod ) {
						ans = mod;
					} ans > mod ans mod {
						ans = mod;
					} ans = mod ans mod System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long L = sc.nextLong();
		long R = sc.nextLong();

		if ( R - L > 2019 ) {
			System.out.println(0);
		} else {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		}
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long L = sc.nextLong();
		long R = sc.nextLong();

		if ( R - L > 2019 ) {
			System.out.println(0);
		} else {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		}
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long L = sc.nextLong();
		long R = sc.nextLong();

		if ( R - L > 2019 ) {
			System.out.println(0);
		} else {
			long ans = 2019;
			for ( long i = L ; i < R ; i++ ) {
				for ( long j = i + 1 ; j <= R ; j++ ) {
					long mod = (i * j) % 2019;
					if ( ans > mod ) {
						ans = mod;
					}
				}
			}
			System.out.println(ans);
		}
	}
}
