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 Julia (0.5.0) (judge verdict: Accepted)

function main()
  
  (L,R) = map(x -> parse(Int,x), split(readline()))
  
  ans = 10^10
  
  if R-L+1 >= 2019
    ans = 0
  else
    for i in L:R-1
      for j in i+1:R
        ans = min(ans,(i*j) % 2019)
      end
    end
  end
  
  println(ans)
  
end

main()