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) {
  var L = parseInt(input.split(" ")[0]);
  var R = parseInt(input.split(" ")[1]);
  var min = 2019;
  if((R - L) >= 2019){
    // console.log(0);
    //	return;
     }
  L = L % 2019;
  R = R % 2019;
  for(var i = L; i < R; i++){
    if(i % 2019 == 0){
       console.log(0);
    	return;
    }
    for(var j = i + 1; j <= R; j++){
      if(j % 2019 == 0){
         console.log(0);
    	return;
         }
      var cal = (i * j) % 2019;
      if(min > cal){
         min = cal;
        if(min == 0){
           console.log(min);
          return;
           }
      }
    }
  }
  console.log(min);
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));