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)

'use strict';
function main(input) {
  const args = input.split(' '),
        L = parseInt(args[0]),
        R = parseInt(args[1]);
  let min = 2019;
  for (let i = L; i <= R-1 && i <= L+2018-1; ++i) {
    if (i % 2019 === 0 || (i+1) % 2019 === 0) {
      min = 0;
      break;
    } else {
      for (let j = i+1; j <= R && j <= L+2018; ++j) {
        let tmp = i*j % 2019;
        if (tmp < min) {
          min = tmp;
        }
      }
    }
  }
  console.log(min);
}

main(require('fs').readFileSync('/dev/stdin', 'utf8'));