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 (1.4.0) (judge verdict: Accepted)

using DataStructures
const double = Float64
const int = Int64

parseint(x) = parse(int, x)
readint() = map(parseint, split(readline()))

function main()
  L,R = readint()
  if L÷2019 < R÷2019
    println(0)
    return
  elseif L ÷ 3 < R ÷ 3 && L÷673 < R÷673 
    println(0)
    return
  else
    mins = typemax(int)
    for i in L:R-1
      for j in i+1:R
        if  (i*j)%2019 < mins
          mins = (i*j)%2019
        end
      end
    end
    println(mins)
    
  end
  
end



main()