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.*;
import java.lang.*;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		long A = sc.nextLong();
		long B = sc.nextLong();
		long C = sc.nextLong();
		long D = sc.nextLong();
		long E = 0;
		long F = Math.max(C,D);
		long G = Math.min(C,D);
		for( long i=1; i*i<=G; i++ ){
			if( G%i==0 ){
				if( F%i==0 ){
					E = (C*D)/i;
				}
			}
		}
		if( F%G==0 ){
			E = F;
		}
		long disC = B/C - (A-1)/C;
		long disD = B/D - (A-1)/D;
		long disCD = B/E - (A-1)/E;
		System.out.println( (B-A+1) + disCD - disC - disD );
	}
}