Problem:
Score : 300 points

Problem Statement

You are given two non-negative integers L and R.
We will choose two integers i and j such that L \leq i < j \leq R.
Find the minimum possible value of (i \times j) \mbox{ mod } 2019.

Constraints

All values in input are integers.

0 \leq L < R \leq 2 \times 10^9

Input

Input is given from Standard Input in the following format:

L R

Output

Print the minimum possible value of (i \times j) \mbox{ mod } 2019 when i and j are chosen under the given condition.

Sample Input 1

2020 2040

Sample Output 1

2

When (i, j) = (2020, 2021), (i \times j) \mbox{ mod } 2019 = 2.

Sample Input 2

4 5

Sample Output 2

20

We have only one choice: (i, j) = (4, 5).

Solution in Pascal (FPC 2.6.2) (judge verdict: Accepted)

Program Catcoder4;
//uses crt;
var l,r,i,j,min :longint;
//--------------------------
begin
readln(l,r);
min:=2019;
if r-l+1 >=2019 then Writeln(0) else begin
                                     for i:=l to r-1 do
                                     for j:=i+1 to r do begin
                                                        if ((i mod 2019)*(j mod 2019)) mod 2019 < min then min :=((i mod 2019)*(j mod 2019)) mod 2019;
                                                        end;
                                     Writeln(min);
                                     end;
//readln;
end.