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 Go (1.6) (judge verdict: Wrong Answer)

package main

import(
    "fmt"
    "math"
)

func main() {
    var l, r int
    fmt.Scan(&l, &r)
    var min, second int
    var num int
    min = 2020
    second = 2020
    for i:=l;i <=r;i++ {
        num = int(math.Abs(float64(i%2019)))
        if min > num{
            second = min
            min = i%2019
        } else if second > num && min < num{
            second = num
        } 
    }
    fmt.Println(min*second)
}