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 Java8 (OpenJDK 1.8.0) (judge verdict: Wrong Answer)

import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong()-1;
		long b = sc.nextLong();
		long c = sc.nextLong();
		long d = sc.nextLong();
		
		long l = lcm(c,d);

		long countA = a - (a/c + a/d - a/l);
		long countB = b - (b/c + b/d - b/l);
		
		long ans = countB - countA;
		System.out.println(ans);
		
		
		sc.close();
	}
	
	public static int lcm(long a, long b)  {
		long c = a * b;
		long temp;
		while ((temp = a % b) != 0) {
			a = b;
			b = temp;
		}
		
		return (int)(c/b);
	}
	
}