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 JavaScript (node.js v5.12) (judge verdict: Wrong Answer)

function Main(input){
  input = input.split("\n");
  inputStr = input[0].split(" ");
  const L = Number.parseInt(inputStr[0]);
  const R = Number.parseInt(inputStr[1]);
  
  var min = 2018;  
  if ( L * R > 2019){
    if ( R - L < 2019) {
      const L2 = L % 2019;
      const R2 = R % 2019;
       
      for(var i1 = L; i1 < R; i1++){
        for(var i2 = i1+1 ; i2 < R+1 ; i2++){
          min = Math.min(min,i1 * i2 % 2019);
          if(min === 0) { break; }
        }
        if(min === 0) { break; }
      }
	  console.log(min);
    } else {
      console.log(0);
    }
  } else {
    //LとRの積が2019を超えないなら計算する必要がない
    console.log(L * (L+1));
  }
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));