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)

// A以上B以下の数 - Cで割り切れる数 - Dで割り切れる数 + CとDの最小公倍数で割れる数
fun main(args: Array<String>) {
    val (a,b,c,d) = readLine()!!.split(' ').map { s -> s.toLong() }
    //val (n,x) = readLine()!!.split(" ").map { s -> s.toLong() }
    //val L = readLine()!!.split(" ").map { s -> s.toLong() }
    val c_cnt = countNumber(a,b,c)
    val d_cnt = countNumber(a,b,d)
    val cd_cnt = countNumber(a,b,lcm(c,d))
    println(c_cnt)
    println(d_cnt)
    println(cd_cnt)

    println(b-a+1-c_cnt-d_cnt+cd_cnt)
}

fun countNumber(a: Long,b: Long,x: Long): Long {
    var cnt = (((b-a) + 1) / x).toLong()
    cnt += if (x - (a % x) <= (b-a+1) % x) 1L else 0L
    cnt += if ((a % x) == 0L && (b-a+1) % x != 0L) 1L else 0L
    return(cnt)
}

fun gcd(a: Long, b: Long): Long = if(a < b) gcd(b, a) else if(b == 0L) a else gcd(b, a % b)
fun lcm(a: Long, b: Long): Long = (a * b) / gcd(a, b)