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 (a, b, c, d) = readLine()!!.split(" ").map{ it.toLong()}
    val lcm = lcm(c, d)
    println(b - (b / c) - (b / d) + (b / lcm) - (a - (a / c) - (a / d) + (a / lcm)))
}
fun gcd(a: Long, b: Long): Long {
    if (b == 0L) return a
    return if (a < b)gcd(b, a) else gcd(b, a % b)
}
fun lcm(a: Long, b: Long): Long {
    return a * b / gcd(a, b)
}