Problem:
Score : 300 points

Problem Statement

You are given four integers A, B, C, and D. Find the number of integers between A and B (inclusive) that can be evenly divided by neither C nor D.

Constraints

1\leq A\leq B\leq 10^{18}

1\leq C,D\leq 10^9

All values in input are integers.

Input

Input is given from Standard Input in the following format:

A B C D

Output

Print the number of integers between A and B (inclusive) that can be evenly divided by neither C nor D.

Sample Input 1

4 9 2 3

Sample Output 1

2

5 and 7 satisfy the condition.

Sample Input 2

10 40 6 8

Sample Output 2

23

Sample Input 3

314159265358979323 846264338327950288 419716939 937510582

Sample Output 3

532105071133627368

Solution in Kotlin (1.0.0) (judge verdict: Wrong Answer)

fun main(args:Array<String>){
    val line = readLine()!!.split(" ").map{it.toLong()}
    val a = line[0]
    val b = line[1]
    val c = line[2]
    val d = line[3]
    val result = b-a+1L-((b/c + b/d - b/(c*d))-(a/c + a/d - a/(c*d)))
    println(result)
}